Method and device for switching uplink resource types in an ambient-iot device

Abstract

The present disclosure relates to methods and devices for enabling a radio access network, RAN, to control the selection of an uplink resource type to be used by a user equipment, UE (20), among different types of uplink resources simultaneously allocated to this UE, wherein the UE comprises a wireless device (25) comprising an energy harvesting unit (254) for collecting ambient energy.

Description

Method and device for switching uplink resource types in an ambient-loT deviceTechnical field

[0001] The present disclosure relates to wireless communication systems and relates more specifically to methods and devices for enabling a radio access network, RAN, to control the selection of an uplink resource type to be used by a wireless device, among different types of uplink resources simultaneously allocated to this wireless device.Background

[0002] The internet of things (loT) allows various devices to connect to the internet to send data, receive instructions, or both. Tens of billions of loT devices are already deployed and the global number of loT devices is expected to increase rapidly. Thus, massive connectivity is needed. However, powering these billions of loT devices is a critical challenge, and deploying power cables or regularly replacing / recharging batteries is not a viable solution.

[0003] 3GPP (Third Generation Partnership Project) is investigating new loT technologies to open new markets within 3GPP systems, whose number of connections and / or device density can be orders of magnitude higher than existing 3GPP loT technologies, and which can provide complexity and power consumption orders-of-magnitude lower than existing 3GPP technologies such as narrow-band-loT (NB-loT) and long-term evolution-machine- type communications (LTE-MTC). More specifically, 3GPP is currently defining Ambient- loT (A-loT) technologies (see e.g., the technical report TR 38.848 V18.0.0) aiming at enabling ultra-low power consumption loT devices, which could be either batteryless devices with no energy storage capability (performing backscattering transmission) or devices with energy storage that do not need to be replaced or recharged manually (performing wire-free energy harvesting (EH) from one or more energy sources).

[0004] By “ultra-low power consumption” devices, or “A-loT” devices, we mean devices having a peak power consumption lower than 1 mW, or even lower than 100 pW or lower than 10 pW. For instance, Ambient-loT currently aims at enabling A-loT devices having the following characteristics: around 1 pW peak power consumption with energy storage, with neither downlink (DL) nor uplink (UL) amplification in the device (the device’s UL transmission is backscattered on a carrier wave provided externally), below a few hundred pW peak power consumption with energy storage, with DL and / or UL amplification in the device (the device’s UL transmission may be generated internally by the device or be backscattered on a carrier wave provided externally).

[0005] In some cases, such A-loT devices may be allocated, at the same time, different types of uplink resources which may be used for transmitting uplink data. For example, a A-loT device may be allocated simultaneously with (contention-based) random-access channel (RACH) uplink resources, (common or dedicated) configured grant (CG) resources and scheduling request (SR) resources.

[0006] In such a case, it is not clear for the radio access network, RAN, which uplink resources a given A-loT device will perform uplink data transmission. Also, this might increase the latency of uplink data transmission (e.g., if the A-loT device selects contentionbased uplink resources instead of contention free uplink resources) as well as increase collision probability on contention-based uplink resources if many A-loT devices attempt simultaneously to transmit uplink data during the same uplink transmission occasion.Summary

[0007] The present disclosure aims at improving the situation. In particular, the present disclosure aims at addressing at least some of the limitations of the prior art discussed above. In particular, the present disclosure aims at proposing a solution for improving the usage of uplink resources when wireless devices such as A-loT devices are simultaneously allocated with different types of uplink resources (RACH, CG, SR, etc.).

[0008] For that purpose, it is proposed to enable the RAN to control, to some extent at least, the selection of an uplink resource type to be used by a wireless device, among different types of uplink resources simultaneously allocated to this wireless device. Hence, the uplink resource type selection is more under the control of the RAN, and this enables reducing latency and / or collision probability for wireless devices such as A-loT devices.

[0009] According to a first aspect, the present disclosure relates to a method for exchanging data in a wireless communication system, the method being 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, the wireless device further comprising a communication unit configured to exchange data with a radio access network, RAN, of the wireless communication system, wherein, the wireless device being allocated with different types of uplink resources, the method comprises, in response to determining that uplink data is to be sent to the RAN: transmitting uplink data by using a first type of uplink resources among the different types of uplink resources allocated to the wireless device, evaluating an uplink resource type switching criterion, in response to the uplink resource type switching criterion being verified: transmittinguplink data by using a second type of uplink resources among the different types of uplink resources allocated to the wireless device.

[0010] In some embodiments, the method according to the first aspect can further comprise one or more of the following optional features, considered either alone or in any technically possible combination.

[0011] In some embodiments of the method according to the first aspect, the uplink resource type switching criterion is verified in response to receiving an uplink resource type switching triggering signal from the RAN.

[0012] In some embodiments of the method according to the first aspect, the at least two different types of uplink resources allocated to the wireless device comprise: random-access channel, RACH, uplink resources, and configured grant, CG, uplink resources.

[0013] In some embodiments of the method according to the first aspect, the first type of uplink resources corresponds to the RACH uplink resources and the second type of uplink resources corresponds to the CG uplink resources.

[0014] In some embodiments of the method according to the first aspect, the first type of uplink resources corresponds to contention-based uplink resources and the uplink resource type switching criterion is verified in response to determining that the number of retransmissions in the first type of uplink resources reaches a predetermined maximum number of retransmissions.

[0015] In some embodiments of the method according to the first aspect, the maximum number of retransmissions is determined based on information received in system information broadcasted by the RAN and / or in a signaling message addressed specifically to the wireless device or to a group of wireless devices which includes said wireless device.

[0016] In some embodiments of the method according to the first aspect, the information related to the maximum number of retransmissions is received in a response from the RAN to a user equipment, UE, capability message sent by the wireless device, or in an uplink transmission triggering signal transmitted by the RAN, or in a wake-up signal transmitted by the RAN 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 determining that uplink data is to be transmitted comprises receiving an uplink transmission triggering signal from the RAN.

[0018] In some embodiments of the method according to the first aspect, the uplink transmission triggering signal is a wake-up signal that transitions the wireless device from a sleep mode to an active mode or is a signaling message received after receiving a wake-up signal.

[0019] 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 carry out a method according to any one of the embodiments of the first aspect.

[0020] 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.

[0021] According to a fourth aspect, the present disclosure relates to a method for exchanging data in a wireless communication system, the method being 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 which 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 method comprises transmitting to the wireless device information related to a switching between different types of uplink resources allocated to the wireless device.

[0022] In some embodiments, the method according to the fourth aspect can further comprise one or more of the following optional features, considered either alone or in any technically possible combination.

[0023] In some embodiments of the method according to the fourth aspect, the information related to a switching between different types of uplink resources allocated to the wireless device comprises an uplink resource switching triggering signal and / or an information related to a maximum number of retransmissions allowed on contention-based uplink resources.

[0024] In some embodiments of the method according to the fourth aspect, the uplink resource type switching triggering signal includes an indication of the type of uplink resources, among the different uplink resources allocated to the wireless device, to be used after switching.

[0025] In some embodiments, the method according to the fourth aspect comprises determining whether an uplink resource type switching triggering signal is to be transmitted, and / or the indication included thereof, based on at least one characteristic of uplink data to be transmitted by the wireless device.

[0026] In some embodiments of the method according to the fourth aspect, the information related to the maximum number of retransmissions is broadcasted in system information broadcasted and / or is transmitted in a signaling message addressed specifically to the wireless device or to a group of wireless devices which includes said wireless device.

[0027] In some embodiments, the method according to the fourth aspect comprises transmitting an uplink transmission triggering signal to the wireless device as an indication that uplink data is to be transmitted to the BS by the wireless device.

[0028] In some embodiments of the method according to the fourth aspect, the uplink transmission triggering signal is a signaling message addressed specifically to the wireless device or to a group of wireless devices which includes said wireless device.

[0029] In some embodiments of the method according to the fourth aspect, the uplink transmission triggering signal is a wake-up signal that transitions the wireless device from a sleep mode to an active mode or is a signaling message transmitted after transmitting a wake-up signal.

[0030] In some embodiments, the method according to the fourth aspect comprises starting to transmit an energy harvesting signal to the wireless device before transmitting the uplink transmission triggering signal to said wireless device.

[0031] 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 carry out a method according to any one of the embodiments of the fourth aspect.

[0032] According to a sixth aspect, the present disclosure relates to a method for exchanging data in a wireless communication system, the method being 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, the wireless device further comprising a communication unit configured to exchange data with a radio access network, RAN, of the wireless communication system, wherein, the wireless device being allocated with different types of uplink resources, the method comprises: receiving an uplink transmission triggering signal from the RAN, selecting a type of uplink resources among the different types of uplink resources allocated to the wireless device, based on selection information received from the RAN, transmitting uplink data by using the selected type of uplink resources.

[0033] In some embodiments, the method according to the sixth aspect can further comprise one or more of the following optional features, considered either alone or in any technically possible combination.

[0034] In some embodiments, the method according to the sixth aspect comprises receiving the selection information in a signaling message addressed specifically to the wireless device, wherein the signaling message is received after an authentication of the wirelessdevice by the RAN and before receiving the uplink transmission triggering signal.

[0035] In some embodiments of the method according to the sixth aspect, the signaling message addressed specifically to the wireless device is a response from the RAN to a user equipment, UE, capability message sent by the wireless device.

[0036] In some embodiments, the method according to the sixth aspect comprises receiving the selection information in system information broadcasted by the RAN.

[0037] In some embodiments of the method according to the sixth aspect, the selection information is received in the uplink transmission triggering signal or in a wake-up signal received from the RAN that transitions the wireless device from a sleep mode to an active mode before receiving the uplink transmission triggering signal from the RAN.

[0038] In some embodiments of the method according to the sixth aspect, the selection information includes an uplink resource type identifier.

[0039] In some embodiments of the method according to the sixth aspect, the uplink resource type identifier is provided as a bit vector.

[0040] In some embodiments of the method according to the sixth aspect, the different types of uplink resources allocated to the wireless device include at least two among the following uplink resource types: random-access channel, RACH, uplink resources, configured grant, CG, uplink resources, scheduling request, SR, uplink resources.

[0041] In some embodiments of the method according to the sixth aspect, the uplink transmission triggering signal is a wake-up signal that transitions the wireless device from a sleep mode to an active mode or is a signaling message received after receiving a wakeup signal.

[0042] According to a seventh aspect, the present disclosure relates to a wireless device comprising at least one memory and at least one processor configured to carry out a method according to any one of the embodiments of the sixth aspect.

[0043] According to an eighth 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.

[0044] According to a ninth aspect, the present disclosure relates to a method for exchanging data in a wireless communication system, the method being 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 which comprises an energy harvesting unit configured to convert ambient energy into electrical energy that isstored in an energy storage unit of the wireless device, wherein the method comprises: transmitting to the wireless device selection information enabling the wireless device to select a type of uplink resources to be used among different types of uplink resources allocated to the wireless device, transmitting an uplink transmission triggering signal to the wireless device as an indication that uplink data is to be transmitted to the BS by the wireless device.

[0045] In some embodiments, the method according to the ninth aspect can further comprise one or more of the following optional features, considered either alone or in any technically possible combination.

[0046] In some embodiments of the method according to the ninth aspect, the selection information is transmitted in a signaling message addressed specifically to the wireless device, wherein the signaling message is transmitted after an authentication of the wireless device by the BS and before transmitting the uplink transmission triggering signal.

[0047] In some embodiments of the method according to the ninth aspect, the signaling message addressed specifically to the wireless device is a response from the BS to a user equipment, UE, capability message sent by the wireless device.

[0048] In some embodiments of the method according to the ninth aspect, the selection information is broadcasted in system information.

[0049] In some embodiments of the method according to the ninth aspect, the selection information is transmitted in the uplink transmission triggering signal or in a wake-up signal that transitions the wireless device from a sleep mode to an active mode before the transmission of the uplink transmission triggering signal.

[0050] In some embodiments, the method according to the ninth aspect comprises determining the selection information based on at least one characteristic of uplink data to be transmitted by the wireless device.

[0051] In some embodiments of the method according to the ninth aspect, the uplink transmission triggering signal is a signaling message addressed specifically to the wireless device or to a group of wireless devices which includes said wireless device.

[0052] In some embodiments of the method according to the ninth aspect, the uplink transmission triggering signal is a wake-up signal that transitions the wireless device from a sleep mode to an active mode or is a signaling message transmitted after transmitting a wake-up signal.

[0053] In some embodiments, the method according to the ninth aspect comprises starting to transmit an energy harvesting signal to the wireless device before transmitting the uplink transmission triggering signal to said wireless device.

[0054] According to a tenth aspect, the present disclosure relates to a base station, BS, comprising at least one memory and at least one processor configured to carry out a method according to any one of the embodiments of the ninth aspect.

[0055] According to an eleventh aspect, the present disclosure relates to a wireless communication system comprising at least one base station according to any one of the embodiments of the present disclosure and at least one user equipment according to any one of the embodiments of the present disclosure.

[0056] According to a twelfth aspect, the present disclosure relates to a computer program product comprising instructions which, when executed by at least one processor, configure said at least one processor to carry out a method for exchanging data according to any one of the embodiments of the present disclosure. The computer program product can use any programming language, and can be in the form of source code, object code, or in any intermediate form between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0057] According to a thirteenth aspect, the present disclosure relates to a (non-transitory) computer-readable storage medium comprising instructions which, when executed by at least one processor, configure said at least one processor to carry out a method for transmitting control messages according to any one of the embodiments of the present disclosure.Brief description of figures

[0058] The invention will be better understood upon reading the following description, given as an example that is in no way limiting, and made in reference to the figures which show:Figure 1 : schematic representations of different possible topologies of a wireless communication system,Figure 2: a schematic representation of an example of a wireless device, Figure 3: a schematic representation of an example of a BS,Figures 4 and 5: flow charts illustrating examples of methods for exchanging data implemented by a wireless device of a UE and a BS, respectively,Figures 6 and 7: flow charts illustrating other examples of methods for exchanging data implemented by a wireless device of a UE and a BS, respectively.

[0059] In these figures, references identical from one figure to another designate identical or analogous elements. For reasons of clarity, the elements shown are not to scale, unless explicitly stated otherwise.Detailed description

[0060] The detailed description set forth below, with reference to the figures, is intended asa description of various configurations and is not intended to represent the only configurations in which the concepts described herein 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 instance, although 3GPP terminology, from e.g., 5G NR, may be used in this disclosure to exemplify embodiments herein, this should not be seen as limiting the scope of the present disclosure.

[0061] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and / or is implied from the context in which it is used. All references to a / an / the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. Also, the order of steps of any methods disclosed herein, in particular in the figures, is provided only for illustration purposes and is not meant to limit the present disclosure which may be applied with the same steps executed in a different order and / or with all or part of the steps executed in parallel or jointly, unless a step is explicitly described as following or preceding another step and / or where it is implicit that a step must follow or precede another step. Also, in a figure, steps represented surrounded by a dashed line are to be considered as optional for the embodiment represented in this figure. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description.

[0062] Figure 1 represents schematically an example of wireless communication system, which may be for example a 5G NR wireless communication system. More specifically, figure 1 represents a RAN of the wireless communication system, which is used exchange data with UEs 20 via radio signals. For example, the RAN may send data to the UEs 20 (downlink, DL), for instance data received from a core network (CN, not represented in the figures). The RAN may also receive data from the UEs 20 (uplink, UL), which data may be forwarded to the CN.

[0063] In the example illustrated by figure 1 , the RAN comprises one base station, BS, 30. Of course, the RAN may comprise more than one BS 30 to increase the coverage of the wireless communication system. Each of these BSs may be referred to as 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.

[0064] In the example illustrated by figure 1 , only one UE 20 is represented, 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 figure 1 represents schematically an example in which the UE 20 exchanges data (useful data 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 figure 1 represents schematically an example in which the UE 20 exchanges data (useful data 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 may be e.g., a relay, an integrated access and backhaul (I AB) node, another UE 20, a repeater, a reconfigurable intelligent surface (RIS), etc.

[0065] Figure 2 represents schematically an example of a wireless device 25 suitable for implementing any method, discussed in the present disclosure, performed at a UE 20. Basically, the wireless device 25 corresponds to an apparatus that provides wireless connectivity with the RAN of the wireless communication system, and that can be used to exchange data with said RAN. The wireless device 25 is for example an A-loT device, i.e. , a wireless device having a peak power consumption lower than 1 mW, or even lower than 100 pW, or even lower than 10 pW.

[0066] Such a wireless device 25 may be included in a UE 20, as illustrated by figure 2. The UE 20 may for instance be a cellular 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 (loT) equipment, like a wireless camera, a smart sensor, a smart meter, smart glasses, a vehicle (manned or unmanned), a global positioning system device, etc., or any other equipment that may run applications that need to exchange data with remote recipients, via the wireless device 25.

[0067] As illustrated by figure 2, the wireless device 25 comprises one or more processors 250 and one or more memories 251. The one or more processors 250 may include for instance 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 nonvolatile memories (magnetic hard disk, solid-state disk, 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-code 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 at a UE’s side, according to any one of the embodiments disclosed herein.

[0068] As illustrated by figure 2, the wireless device 25 comprises also 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 instance be a 3G, 4G, 5G, NR, WiFi, WiMax, etc. transceiver or the like. In preferred embodiments, the (wireless) communication unit 253 comprises a 5G NR wireless communication unit.

[0069] As discussed above, the communication unit 253 may comprise in some examples neither downlink (DL) nor uplink (UL) amplification capabilities (the UL transmission is backscattered on a carrier wave provided externally). In other examples, the communication unit 253 may comprise DL and / or UL amplification (the UL transmission may be generated internally by the wireless device or be backscattered on a carrier wave provided externally).

[0070] As illustrated by figure 2, the wireless device 25 comprises also an energy harvesting unit 254 and an energy storage unit 255 of the wireless device.

[0071] The energy storage unit 255 may be any type of electrical energy accumulator, and may comprise e.g., one or more capacitors, one or more batteries, etc. The energy storage unit 255 is used to provide electrical energy to the other equipment of the wireless device 25 which require electrical energy, such as the one or more processors 250, the one or more memories 251 and, in some examples, the (wireless) communication unit 253.

[0072] The energy harvesting unit 254 is configured to convert ambient energy into electrical energy that is stored in the energy storage unit 255. By “ambient energy” we mean energy from energy sources that are external to the wireless device 25, which is received at the wireless device 25 without any wires between the energy sources and the wireless device 25. Hence, the energy harvesting unit 254 is such that the wireless device 25 may operate in an autonomous manner, without having to replace or recharge manually the energy storage unit 255. The energy harvesting unit 254 may for example collect energy from various energy sources including solar, thermal, motion or vibration, radiofrequency (RF), etc.

[0073] In preferred embodiments, the energy harvesting unit 254 comprises at least a radio unit configured to convert RF signals into electrical energy that is stored in the energy storage unit 255. These RF signals may for instance be external RF signals, i.e., RF signals which do not originate from within the wireless communication system itself but from RF sources which are external to 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 thereof, the RF signals may originate from within the wireless communication system, for example from BSs 30 of the RAN which may transmit an energy harvesting (RF) signal to(A-loT) wireless devices 25 in their coverage, and / or from equipment separate from the BSs 30 but deployed to enable energy harvesting at the (A-loT) wireless devices 25 of the wireless communication system. In some examples, when RF signals are used to collect electrical energy into the energy storage unit 255, the energy harvesting unit 254 may be included in the (wireless) communication unit 253.

[0074] Figure 3 represents schematically an example of a BS 30 suitable to implement any method, discussed in the present disclosure, performed by the RAN.

[0075] As illustrated by figure 3, the BS 30 comprises one or more processors 300 and one or more memories 301. The one or more processors 300 may include for instance 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 memories (magnetic hard disk, solid-state disk, 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 programcode 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’s side, according to any one of the embodiments disclosed herein.

[0076] As illustrated by figure 3, the BS 30 comprises also a wireless communication unit 303, configured to exchange data with UEs 20 using radio signals, and more specifically with (wireless) communication units 253 of wireless devices 25 included in these UEs 20. The wireless communication unit 303 may for instance 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 comprises a 5G NR transceiver. In some examples, the wireless communication unit 303 may also transmit carrier waves to the wireless devices 25 which perform uplink backscattering transmissions.

[0077] As illustrated by figure 3, the BS 30 may comprise also, in some examples, 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 optical) and / or wireless.

[0078] As illustrated by figure 3, the BS 30 may comprise also, in some examples, an energy harvesting signal generator 305, which generates energy harvesting (RF) signals which enable wireless devices 25 in its coverage to collect electrical energy in their energy storage units 255, via their energy harvesting units 254. The energy harvesting (RF) signals may take any suitable form enabling the energy harvesting units 254 to store electrical energy in the energy storage units 255 of the wireless devices 25. The choice of a specificenergy harvesting (RF) signal format consists in a specific and non-limitative embodiment of the present disclosure. As mentioned above, when present, such energy harvesting (RF) signals may alternatively, or in combination thereof, be generated by other equipment separate from BSs 30 of the RAN.

[0079] As discussed above, the present disclosure aims at enabling the RAN to reduce collision probability and latency for the wireless devices 25 by controlling to some extent at least the selection of a type of uplink resources to be used by a wireless device 25, when different types of uplink resources are simultaneously allocated to this wireless device 25. Hence, the uplink resource type selection is more under the control of the RAN, and this enables reducing latency and / or collision probability for wireless devices 25.

[0080] For that purpose, in some embodiments, it is proposed to enable the RAN to provide a wireless device 25 with selection information, instructing the wireless device 25 of which type of uplink resources should be used among the different types of uplink resources allocated to this wireless device 25. Alternatively, or in combination thereof, it is proposed in some embodiments to enable the RAN to provide a wireless device 25 with switching information, instructing the wireless device 25 of when to switch from a first type to a second type of allocated uplink resources.

[0081] As discussed above, the wireless device 25 is assumed to have different types of allocated uplink resources, i.e., different types of uplink resources it may use to transmit uplink data. For example, the wireless device 25 may be allocated with different types of contention-based uplink resources and / or different types of contention-free uplink resources.

[0082] By “contention-based uplink resources”, we mean uplink resources which are shared by a plurality of wireless devices 25, on which each of these wireless devices 25 can decide on its own to transmit messages, which messages may therefore collide with messages from other wireless devices 25 with which these uplink resources are shared.

[0083] By “contention-free uplink resources”, we mean uplink resources which are allocated to a specific wireless device 25 and cannot be used by other wireless devices 25.

[0084] Examples of contention-based uplink resources in e.g., a 5G NR wireless communication system include RACH uplink resources, which are used by the wireless devices 25 to establish a communication with a BS 30 of the RAN. Such RACH uplink resources are allocated to the wireless devices 25 regardless their radio resource control, RRC, state (e.g., RRC connected (RRC_CONNECTED), RRC idle (RRCJDLE), or RRC inactive (RRC NACTIVE) state).

[0085] Other examples of contention-based uplink resources in e.g., a 5G NR wireless communication system include common configured grant, CG, uplink resources. Suchcommon CG uplink resources are for example allocated to wireless devices 25 in RRC_CONNECTED state. By “common”, we mean that these CG uplink resources can be shared by a plurality of wireless devices. In turn, a 5G NR wireless communication system may also allocate dedicated CG uplink resources to a specific wireless device 25 in RRC_CONNECTED state, which are to be used only by this specific wireless device 25 and are therefore contention-free uplink resources.

[0086] Other examples of contention-free uplink resources in e.g., a 5G NR wireless communication system include scheduling request, SR, uplink resources. Indeed, the SR procedure enables a wireless device 25 to request uplink resources for transmitting uplink data to the RAN. For that purpose, the wireless device 25 may be allocated with SR uplink resources which may be used to transmit an uplink request (SR message, for requesting additional uplink resources for an upcoming transmission). Such SR uplink resources can for example be allocated by the RAN to a wireless device 25 in RRC_CON NESTED state or in RRCJNACTIVE state.

[0087] For example, the wireless device 25 may be allocated with at least two among the following uplink resource types:RASH uplink resources (usually always available to the wireless device 25), CG uplink resources (common and / or dedicated), SR uplink resources.

[0088] We now present non-limitative examples of how such uplink resource type selection and / or switching control may be implemented.

[0089] Uplink resource type selection

[0090] Figure 4 represents a diagram showing steps of an exemplary embodiment of a method 40 for exchanging data, which is implemented by a wireless device 25 of a UE 20. Figure 5 represents a diagram showing corresponding steps of an exemplary embodiment of a method 50 for exchanging data, which is implemented by a BS 30 of the RAN.

[0091] As illustrated by figure 4, the method 40 for exchanging data comprises a step S40 of receiving selection information from the RAN. The selection information corresponds to information to be used by the wireless device 25 for selecting a type of uplink resources to be used among the different types (RACH, CG, SR, etc.) of uplink resources allocated to the wireless device 25, i.e., in which the wireless device 25 is allowed to transmit uplink data without requiring further consent from the RAN.

[0092] As illustrated by figure 4, the method 40 for exchanging data comprises also a step S41 of receiving an uplink transmission triggering signal from the RAN. The purpose of the uplink transmission triggering signal is to indicate to the wireless device 25 that it can initiatean uplink transmission on uplink resources allocated to the wireless device 25.

[0093] To reduce its electrical energy consumption, the wireless device 25 may be placed in a sleep mode. In such a case, the wireless device 25 needs to transition to an active mode to be able to perform the uplink data transmission. Such a transition may be triggered by the RAN, by sending a wake-up signal to the wireless device 25. In such a case, the uplink transmission triggering signal may correspond to the wake-up signal which transitions the wireless device 25 from a sleep mode to an active mode, or it may be transmitted by the RAN after it has transmitted a wake-up signal to the wireless device 25.

[0094] As illustrated by figure 4, the method 40 for exchanging data comprises also: a step S42 of selecting a type of uplink resources among the different types of uplink resources allocated to the wireless device 25, based on the selection information received from the RAN, and a step S43 of transmitting uplink data by using the selected type of uplink resources (provided the wireless device 25 has uplink data to transmit, and / or has enough electrical energy stored in its energy storage unit 255, etc.).

[0095] It should be noted that, during step S42, the wireless device 25 may, in some cases, select more than one type of uplink resources to be used for transmission.

[0096] As indicated above, the order of the steps is provided only for illustration purposes and is not meant to limit the present disclosure. This applies particularly to the step S40 of receiving the selection information, the step S41 of receiving the uplink transmission triggering signal and the step S42 of selecting a type of uplink resources to be used. Of course, the step S40 of receiving the selection information needs to be carried out before the step S42 of selecting a type of uplink resources based on the selection information. For example, the step S40 of receiving the selection information may be carried out: before the step S41 of receiving the uplink transmission triggering signal, or simultaneously with the step S41 of receiving the uplink transmission triggering signal (i.e., the selection information is included in the uplink transmission triggering signal), or after the step S41 of receiving the uplink transmission triggering signal.

[0097] The same applies also for the step S42 of selecting a type of uplink resources to be used, which may be carried out e.g., before or after the step S41 of receiving the uplink transmission triggering signal, keeping in mind that it needs to be carried out after the step S40 of receiving the selection information. In preferred embodiments, the step S42 of selecting the type of uplink resources to be used is carried out in response to receiving an uplink transmission triggering signal from the RAN. In the sequel, we assume in a non-limitative manner that the step S42 of selecting the type of uplink resources is carried out after having received the uplink transmission triggering signal from the RAN.

[0098] The selection information may be received in any type of signaling message and the choice of a specific type of signaling message corresponds to a specific but non-limitative embodiment of the present disclosure.

[0099] For example, the selection information is received in a signaling message addressed specifically to the wireless device 25, e.g., received after an authentication of the wireless device 25 by the RAN and before receiving the uplink transmission triggering signal. For example, this signaling message addressed specifically to the wireless device 25 may be a response from the RAN to a UE capability message (RRC message) sent by the wireless device 25. For example, the selection information may be determined by the RAN based on the UE capability message.

[0100] According to another example, the selection information is received in system information broadcasted by the RAN, preferably before receiving the uplink transmission triggering signal.

[0101] According to another example, the selection information is received in the uplink transmission triggering signal, or in a wake-up signal received from the RAN that transitions the wireless device 25 from a sleep mode to an active mode (e.g., transmitted by the RAN to make sure that the wireless device 25 is in the active mode when the RAN transmits the uplink transmission triggering signal to the wireless device 25).

[0102] When the selection information is received in system information broadcasted by the RAN, or in e.g., a response to the UE capability message transmitted by the wireless device 25, the configuration of the selection information may be static and may remain valid for all uplink transmissions by the wireless device 25. In turn, transmitting the selection information in the wake-up signal, if any, or in the uplink transmission triggering signal enables to dynamically change the selection information to be used at each uplink transmission.

[0103] It should be noted that both approaches can also be combined in some embodiments, by receiving different selection information over time. For example, the wireless device 25 may receive a static configuration of the selection information, to be used by default, e.g., in system information or in a response to a UE capability message. Subsequently, the wireless device 25 may receive a dynamic configuration of the selection information, e.g., in the wake-up signal or in the uplink transmission triggering signal, which replaces temporarily the static configuration (e.g., for only a predetermined number of triggered uplink transmissions). This replacement may also be permanent, in which case the received selection information becomes the new static configuration. Dynamicallyconfiguring the selection information enables a better control of the latency and collision probability by the RAN.

[0104] The selection information may use any suitable format and the choice of a specific format consists in a specific but non-limitative embodiment of the present disclosure. The format may, in some cases, depend on whether it corresponds to a static configuration or a dynamic configuration.

[0105] For example, in the case of a dynamic configuration, the RAN knows which different types of uplink resources are allocated to the wireless device 25, such that the selection information may correspond directly to the specific type of uplink resources to be used among the different uplink resource allocated to the wireless device 25. Hence, the RAN directly selects the type of uplink resource to be used, e.g., based on at least one characteristic of uplink data to be transmitted by the wireless device 25 (and based on the different types of uplink resources effectively allocated to the wireless device 25). For example, the at least on characteristic of the uplink data to be transmitted may comprise a traffic class (priority level, latency requirement, etc.) and / or a category of UE 20, etc. In some examples, the RAN may also select the type of uplink resource to be used by the wireless device 25 based on a load level of the RAN. It should be noted that the RAN may also transmit a selection information indicating directly more than one specific type of uplink resources to be used by the wireless device 25, in which case the wireless device 25 may for example use all or part of the specific uplink resource types indicated by the RAN.

[0106] In the case of a static configuration, the selection information may correspond to information which enables the wireless device 25 to perform the selection based on an uplink transmission context. For example, the uplink transmission context may depend on the different types of uplink resources effectively allocated to the wireless device 25 when the uplink transmission triggering signal is received, on the traffic class of the uplink data to be transmitted, on the UE category, etc. For example, the selection information may correspond to a mapping between different traffic classes and respective uplink resource types to be used. In some cases, it is possible to associate in the mapping more than one uplink resource type to each traffic class, ranked according to a preference order. In such a case, the wireless device 25 identifies the uplink resource types associated to its traffic class, and then selects the best ranked uplink resource type which corresponds to an uplink resource type that is effectively allocated to the wireless device 25.

[0107] In some cases, the selection information includes an uplink resource type identifier which indicates one specific type of uplink resource to be used. For example, the uplink resource type identifier may be provided as a bit vector. For example, the bit vector may becomposed of two (2) bits. For example, it is possible to use a 2-bits bit vector as follows: a bit vector set to ‘00’ may be used to indicate that the wireless device 25 shall use RACH uplink resources, a bit vector set to ‘0T may be used to indicate that the wireless device 25 shall use CG uplink resources, a bit vector set to ‘10’ may be used to indicate that the wireless device 25 shall use SR uplink resources, etc.

[0108] As discussed above, figure 5 represents a diagram showing corresponding steps of an exemplary embodiment of a method 50 for exchanging data, which may be implemented by a BS 30 when the wireless device 25 implements the method 40 for exchanging data illustrated by figure 4.

[0109] As illustrated by figure 5, the method 50 for exchanging data comprises: a step S50 of transmitting to the wireless device 25 selection information enabling the wireless device 25 to select a type of uplink resources to be used among different types of uplink resources allocated to the wireless device 25 (received by the wireless device 25 during step S40), a step S51 of transmitting an uplink transmission triggering signal to the wireless device 25 as an indication that uplink data is to be transmitted to the BS 30 by the wireless device 25 (received by the wireless device 25 during step S41), a step S52 of receiving uplink data from the wireless device 25 (provided the wireless device 25 has uplink data to transmit, and / or has enough electrical energy stored in its energy storage unit 255, etc.).

[0110] All that has been said for the order of steps S40 and S41 in figure 4 applies similarly to steps S50 and S51 in figure 5 (e.g., the order may vary, and they may correspond to a same step if the selection information is included in the uplink triggering transmission signal). Also, the step S50 of transmitting selection information may be repeated for e.g., transmitting a static configuration and a dynamic configuration.

[0111] As discussed above, the selection information may be transmitted in a signaling message addressed specifically to the wireless device 25 (e.g., in response to a UE capability message from the wireless device 25), or in system information broadcasted by the BS 30, or in the uplink transmission triggering signal, or in a wake-up signal that transitions the wireless device 25 from a sleep mode to an active mode (to prepare the wireless device 25 for the reception of the uplink transmission triggering signal), etc.

[0112] It should be noted that any suitable format may be used for the uplink transmission triggering signal, and the choice of a specific format for the uplink transmission triggeringsignal corresponds to a specific but non-limitative embodiment of the present disclosure. Also, in some cases, the uplink transmission triggering signal may be a wake-up signal, or it may be a signaling message transmitted after transmitting a wake-up signal.

[0113] As discussed above, the selection information may for example correspond to an indication of one or more specific types of uplink resources to be used (e.g., an uplink resource type identifier), a mapping between different traffic classes and respective uplink resource types to be used, etc.

[0114] In some examples, and as illustrated by figure 5, the method 50 for exchanging data comprises an optional step S53 of determining the selection information based on an uplink transmission context of the wireless device 25 (traffic class, UE category, uplink resource types effectively allocated to the wireless device 25, load level of the BS 30, etc.).

[0115] In examples where the BS 30 comprises an energy harvesting signal generator 305, the BS 30 may for example start transmitting an energy harvesting (RF) signal to the wireless device 25 before transmitting the uplink transmission triggering signal to said wireless device 25. In some cases, the energy harvesting (RF) signal may be used as a wake-up signal that transitions the wireless device 25 to an active mode.

[0116] Uplink resource type switching

[0117] Figure 6 represents a diagram showing steps of an exemplary embodiment of a method 60 for exchanging data, which is implemented by a wireless device 25 of a UE 20. Figure 7 represents a diagram showing corresponding steps of an exemplary embodiment of a method 70 for exchanging data, which is implemented by a BS 30 of the RAN.

[0118] As illustrated by figure 6, the method 60 for exchanging data comprises a step S60 of determining that uplink data is to be sent by the wireless device 25.

[0119] In some examples, the step S60 may consist in detecting that uplink data is available at the UE 20 and should be transmitted by the wireless device 25 to the RAN.

[0120] Alternatively, or in combination thereof, an uplink data transmission may be triggered by the RAN. In such examples, the step S60 may comprise receiving an uplink transmission triggering signal from the RAN. Hence, if the wireless device 25 receives such an uplink transmission triggering signal from the RAN, the wireless device 25 may evaluate whether the uplink data transmission can be initiated, for example in an upcoming UL transmission occasion. Of course, such an uplink data transmission should be initiated only if uplink data is available at the UE 20 or can be collected by the UE in response to receiving the uplink transmission triggering signal from the RAN.

[0121] In the following, we assume in a non-limitative manner that the step S60 of determining that uplink data is to be transmitted comprises receiving an uplink transmissiontriggering signal from the RAN. All that has been said for the step S41 of the method 40 for exchanging data in figure 4 applies similarly for the step S60 of the method 60 of exchanging data in figure 6. In particular, in some cases, the uplink transmission triggering signal may correspond to a wake-up signal which transitions the wireless device 25 from a sleep mode to an active mode, or it may be transmitted by the RAN after it has transmitted a wake-up signal to the wireless device 25.

[0122] As illustrated by figure 6, the method 60 for exchanging data comprises, in response to determining during step S60 that uplink data is to be transmitted, a step S61 of transmitting uplink data by using a first type of uplink resources among the different types of uplink resources allocated to the wireless device.

[0123] As indicated above, the wireless device 25 is allocated with different types of uplink resources (e.g., RACH, CG, SR, etc.). For example, the different types of uplink resources allocated to the wireless device 25 include at least one type of contention-based uplink resources and at least one type of contention-free uplink resources.

[0124] For example, the first type of uplink resources may be a type that is used by default. For example, the type of uplink resources to be used by default when starting to transmit uplink data may be indicated by the RAN as selection information, as a static configuration, as presented previously. According to another example, the first type of uplink resources may be indicated in the uplink transmission triggering signal as selection information, as a dynamic configuration, as presented previously. For example, the first type of uplink resources to be used when starting to transmit data may be indicated by an uplink resource type identifier, as presented previously.

[0125] For example, the first type of uplink resources may correspond by default to contention-based uplink resources such as RACH uplink resources.

[0126] As illustrated by figure 6, the method 60 for exchanging data comprises a step S62 of evaluating an uplink resource type switching criterion.

[0127] If the uplink resource type switching criterion is verified (reference S62a in figure 6), the method 60 for exchanging data comprises a step S63 of transmitting uplink data by using a second type of uplink resources among the different types of uplink resources allocated to the wireless device 25.

[0128] The second type of uplink resources is different from the first type of uplink resources. For example, the first type of uplink resources corresponds to RACH uplink resources and the second type of uplink resources corresponds to CG or SR uplink resources. In other examples, the first type of uplink resources corresponds to CG or SR uplink resources and the second type of uplink resources corresponds to RACH uplink resources.

[0129] For example, the second type of uplink resources may be predefined. For example, the second type of uplink resources may be indicated by the RAN as selection information, as a static configuration, as presented previously. According to another example, the second type of uplink resources may be indicated in the uplink transmission triggering signal as selection information, as a dynamic configuration, as presented previously. For example, the second type of uplink resources to be used when starting to transmit data may be indicated by an uplink resource type identifier, as presented previously. Other examples are also provided hereinbelow.

[0130] If the uplink resource type switching criterion is not verified (reference S62b in figure 6), the method 60 for exchanging data continues to transmit uplink data using the first type of uplink resources. In some examples, and as illustrated by figure 6, the evaluation of the uplink resource type switching criterion may be executed in a recurrent manner, e.g., until the wireless device 25 stops transmitting uplink data.

[0131] For example, the wireless device 25 may evaluate the uplink resource type switching criterion based on switching information received from the RAN. In the non-limitative example of figure 6, the method 60 for exchanging data comprises an optional step S64 of receiving switching information from the RAN.

[0132] In some cases, the switching information may correspond to an uplink resource type switching triggering signal transmitted by the RAN. Hence, the uplink resource type switching criterion is verified in response to receiving an uplink resource type switching triggering signal from the RAN. As discussed above, upon receiving the uplink resource type switching triggering signal, the wireless device 25 switches to a second type of uplink resources which may have been preconfigured, e.g., via selection information. Alternatively, or in combination thereof, the uplink resource type switching triggering signal may include an indication of the second type of uplink resources to be used, for example as an uplink resource type identifier, as presented previously.

[0133] In other examples, the switching information may correspond to one or more parameters that are used to evaluate whether the wireless device 25 should switch to a different type of uplink resources allocated to the wireless de vice 25.

[0134] For example, if the first type of uplink resources corresponds to contention-based uplink resources, the switching information may comprise a maximum number of retransmissions allowed on the contention-based uplink resources. For example, for RACH uplink resources, the wireless device 25 starts by transmitting a RACH preamble that may collide with other transmissions from other wireless devices, in which case the wireless devices 25 attempts to retransmit a RACH preamble until it is detected by the RAN. Toreduce latency and reduce collision probability on the RACH uplink resources, the wireless device 25 compares the number of retransmissions with the maximum number of retransmissions allowed, received as switching information. If the number of retransmissions in the first type of uplink resources reaches the maximum number of retransmissions allowed (reference S62a in figure 6), then the wireless device 25 switches to the second type of uplink resources (e.g., CG or SR uplink resources). In turn (reference S62b in figure 6), then the wireless device 25 continues to transmit uplink data in the first type of uplink resources (e.g., RACH uplink resources).

[0135] According to another example, the switching information may comprise a maximum amount of uplink data, or a validity duration. Hence, the wireless device 25 is allowed in such a case to use the first type of uplink resources for transmitting at most the maximum amount of uplink data, or for at most the validity duration. In such a case, the first type of uplink resources may correspond to CG or SR uplink resources and the second type of uplink resources may correspond to RACH uplink resources.

[0136] Such switching information, comprising one or more parameters to be used during the evaluation (e.g., maximum number of retransmissions, maximum amount of uplink data, validity duration, etc.) is for example received in system information broadcasted by the RAN and / or in a signaling message addressed specifically to the wireless device 25 or to a group of wireless devices which includes said wireless device 25. For example, such switching information is received in a response from the RAN to a UE capability message sent by the wireless device 25, or in the uplink transmission triggering signal transmitted by the RAN, or in a wake-up signal transmitted by the RAN, etc.

[0137] As discussed above, figure 7 represents a diagram showing corresponding steps of an exemplary embodiment of a method 70 for exchanging data, which may be implemented by a BS 30 when the wireless device 25 implements the method 60 for exchanging data illustrated by figure 6.

[0138] As illustrated by figure 7, the method 70 for exchanging data comprises a step S70 of transmitting to the wireless device 25 switching information, i.e., information related to a switching between different types of uplink resources allocated to the wireless device 25 (that the wireless device 25 receives during step S64 and uses during step S62).

[0139] As discussed above, the switching information corresponds for example to an uplink resource switching triggering signal and / or to one or more parameters to be used during the evaluation (e.g., maximum number of retransmissions, maximum amount of uplink data, validity duration, etc.), etc. In some examples, the one or more parameters may be broadcasted in system information broadcasted and / or transmitted in a signaling messageaddressed specifically to the wireless device 25 or to a group of wireless devices which includes said wireless device 25.

[0140] In the example of figure 7, it is assumed in a non-limitative manner that the switching information includes at least an uplink resource type switching triggering signal. As discussed above, in some cases, the uplink resource type switching triggering signal may include an indication of the type of uplink resources, among the different uplink resources allocated to the wireless device, to be used after switching. For example, this indication may be provided as an uplink resource type identifier, as presented previously.

[0141] In the example of figure 7, it is assumed in a non-limitative manner that the wireless device 25 determines that uplink data is to be transmitted when it receives an uplink transmission triggering signal from the RAN. Accordingly, the method 70 for exchanging data comprises a step S71 of transmitting an uplink transmission triggering signal to the wireless device 25 as an indication that uplink data is to be transmitted to the RAN. It should be noted that any suitable format may be used for the uplink transmission triggering signal, and the choice of a specific format for the uplink transmission triggering signal corresponds to a specific but non-limitative embodiment of the present disclosure. Also, in some cases, the uplink transmission triggering signal may be a wake-up signal, or it may be a signaling message transmitted after transmitting a wake-up signal.

[0142] In some cases, and as illustrated by figure 7, the method 70 for exchanging data may comprise an optional step S72 of determining whether an uplink resource type switching triggering signal is to be transmitted, and / or the indication included thereof, based on an uplink transmission context of the wireless device 25 (traffic class, UE category, uplink resource types effectively allocated to the wireless device 25, load level of the BS 30, etc.).

[0143] For example, the BS 30 may determine that an uplink resource type switching triggering signal is to be transmitted when a validity duration has expired since the transmission of the uplink transmission triggering signal, and / or when an amount of uplink data received via the first uplink resource type has reached a predetermined maximum amount of uplink data, etc.

[0144] In examples where the BS 30 comprises an energy harvesting signal generator 305, the BS 30 may for example start transmitting an energy harvesting (RF) signal to the wireless device 25 before transmitting the uplink transmission triggering signal to said wireless device 25.

[0145] It is emphasized that the present disclosure is not limited to the above exemplary embodiments. Variants of the above exemplary embodiments are also within the scope of the present disclosure.

[0146] For example, the present disclosure has been made by considering mainly 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. However, in some cases, the present disclosure may also be applied with wireless devices 25 which do not comprise such an energy harvesting unit, and which operate only with an energy storage unit 255 (which may rechargeable or not).

[0147] Also, the present disclosure has been made by considering mainly the case of A-loT devices. However, the present disclosure can also be used for non-A-loT devices.

[0148] It should also be noted that there can be a coexistence in the wireless communication system between wireless devices 25 which apply the present disclosure and wireless devices which do not apply the present disclosure. For example, the present disclosure may apply e.g. only to A-loT devices and not to non-A-loT devices.

Claims

Claims1. A method (60) for exchanging data in a wireless communication system, the method being implemented by a wireless device (25) of the wireless communication system, wherein the wireless device comprises 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, wherein, the wireless device being allocated with different types of uplink resources, the method comprises, in response to determining that uplink data is to be sent to the RAN:(561) transmitting uplink data by using a first type of uplink resources among the different types of uplink resources allocated to the wireless device,(562) evaluating an uplink resource type switching criterion, in response to the uplink resource type switching criterion being verified: (S63) transmitting uplink data by using a second type of uplink resources among the different types of uplink resources allocated to the wireless device.

2. The method (60) according to claim 1 , wherein the uplink resource type switching criterion is verified in response to receiving an uplink resource type switching triggering signal from the RAN.

3. The method (60) according to any one of the preceding claims, wherein the at least two different types of uplink resources allocated to the wireless device comprise: random-access channel, RACH, uplink resources, and configured grant, CG, uplink resources.

4. The method (60) according to claim 3, wherein the first type of uplink resources corresponds to the RACH uplink resources and the second type of uplink resources corresponds to the CG uplink resources.

5. The method (60) according to any one of the preceding claims, wherein the first type of uplink resources corresponds to contention-based uplink resources and the uplink resource type switching criterion is verified in response to determining that the number of retransmissions in the first type of uplink resources reaches a predetermined maximum number of retransmissions.

6. The method (60) according to claim 5, wherein the maximum number of retransmissions is determined based on information received in system information broadcasted by the RAN and / or in a signaling message addressed specifically to the wireless device or to a group of wireless devices which includes said wireless device.

7. The method (60) according to claim 6, wherein the information related to the maximum number of retransmissions is received in a response from the RAN to a user equipment, UE, capability message sent by the wireless device, or in an uplink transmission triggering signal transmitted by the RAN, or in a wake-up signal transmitted by the RAN that transitions the wireless device from a sleep mode to an active mode.

8. The method (60) according to any one of the preceding claims, wherein the determining that uplink data is to be transmitted comprises receiving an uplink transmission triggering signal from the RAN.

9. A wireless device (25) comprising at least one memory and at least one processor configured to carry out a method (60) 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 (70) 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, wherein the BS is configured to exchange data with a wireless device (25) which comprises 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, wherein the method comprises (S70) transmitting to the wireless device (25) information related to a switching between different types of uplink resources allocated to the wireless device.

12. The method (70) according to claim 11 , wherein the information related to a switching between different types of uplink resources allocated to the wireless device comprises an uplink resource switching triggering signal and / or an information related to a maximum number of retransmissions allowed on contention-based uplink resources.

13. The method (70) according to claim 12, wherein the uplink resource type switching triggering signal includes an indication of the type of uplink resources, among the different uplink resources allocated to the wireless device, to be used after switching.

14. The method (70) according to any one of claims 12 to 13, comprising (S72) determining whether an uplink resource type switching triggering signal is to be transmitted, and / or the indication included thereof, based on at least one characteristic of uplink data to be transmitted by the wireless device.

15. The method (70) according to any one of claims 12 to 14, wherein the information related to the maximum number of retransmissions is broadcasted in system information broadcasted and / or is transmitted in a signaling message addressed specifically to the wireless device or to a group of wireless devices which includes said wireless device.

16. The method (70) according to any one of claims 11 to 15, comprising (S71)transmitting an uplink transmission triggering signal to the wireless device as an indication that uplink data is to be transmitted to the BS by the wireless device (25).

17. A base station, BS (30), comprising at least one memory and at least one processor configured to carry out a method (50) according to any one of claims 11 to 16.

18. A wireless communication system comprising at least one base station (30) according to claim 17 and at least one user equipment (20) according to claim 10.

19. A computer program product (252, 302) comprising instructions which, when executed by at least one processor, configure said at least one processor to carry out a method (60) according to any one of claims 1 to 8 or a method (70) according to any one of claims 11 to 16.

20. A computer-readable storage medium comprising instructions which, when executed by at least one processor, configure said at least one processor to carry out a method (60) according to any one of claims 1 to 8 or a method (70) according to any one of claims 11 to 16.

21. 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, wherein the wireless device comprises 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, wherein, the wireless device being allocated with different types of uplink resources, the method comprises:(541) receiving an uplink transmission triggering signal from the RAN,(542) selecting a type of uplink resources among the different types of uplink resources allocated to the wireless device, based on selection information received from the RAN,(543) transmitting uplink data by using the selected type of uplink resources.

22. The method (40) according to claim 21 , comprising (S40) receiving the selection information in a signaling message addressed specifically to the wireless device, wherein the signaling message is received after an authentication of the wireless device by the RAN and before receiving the uplink transmission triggering signal.

23. The method (40) according to claim 22, wherein the signaling message addressed specifically to the wireless device is a response from the RAN to a user equipment, UE, capability message sent by the wireless device.

24. The method (40) according to any one of claims 21 to 23, comprising (S40) receiving the selection information in system information broadcasted by the RAN.

25. The method (40) according to any one of claims 21 to 24, wherein the selection information is received in the uplink transmission triggering signal or in a wake-up signal received from the RAN that transitions the wireless device from a sleep mode to an active mode before receiving the uplink transmission triggering signal from the RAN.

26. The method (40) according to any one of claims 21 to 25, wherein the selection information includes an uplink resource type identifier.

27. The method (40) according to claim 26, wherein the uplink resource type identifier is provided as a bit vector.

28. The method (40) according to any one of claims 21 to 27, wherein the different types of uplink resources allocated to the wireless device include at least two among the following uplink resource types: random-access channel, RACH, uplink resources, configured grant, CG, uplink resources, scheduling request, SR, uplink resources.

29. A wireless device (25) comprising at least one memory and at least one processor configured to carry out a method (40) according to any one of claims 21 to 28.

30. A user equipment, UE (20), comprising a wireless device according to claim 29.

31. 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, wherein the BS is configured to exchange data with a wireless device (25) which comprises 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, wherein the method comprises:(550) transmitting to the wireless device selection information enabling the wireless device to select a type of uplink resources to be used among different types of uplink resources allocated to the wireless device,(551) transmitting an uplink transmission triggering signal to the wireless device as an indication that uplink data is to be transmitted to the BS by the wireless device.

32. The method (50) according to claim 31 , wherein the selection information is transmitted in a signaling message addressed specifically to the wireless device, wherein the signaling message is transmitted after an authentication of the wireless device by the BS and before transmitting the uplink transmission triggering signal.

33. The method (50) according to claim 32, wherein the signaling message addressed specifically to the wireless device is a response from the BS to a user equipment, UE, capability message sent by the wireless device.

34. The method (50) according to any one of claims 31 to 33, wherein the selection information is broadcasted in system information.

35. The method (50) according to any one of claims 31 to 34, wherein the selection information is transmitted in the uplink transmission triggering signal or in a wake-up signal that transitions the wireless device from a sleep mode to an active mode before the transmission of the uplink transmission triggering signal.

36. The method (50) according to any one of claims 31 to 35, comprising (S53) determining the selection information based on at least one characteristic of uplink data to be transmitted by the wireless device.

37. A base station, BS (30), comprising at least one memory and at least one processor configured to carry out a method (50) according to any one of claims 31 to 36.

38. A wireless communication system comprising at least one base station (30) according to claim 37 and at least one user equipment (20) according to claim 30.

39. A computer program product (252, 302) comprising instructions which, when executed by at least one processor, configure said at least one processor to carry out a method (40) according to any one of claims 21 to 28 or a method (50) according to any one of claims 31 to 36.

40. A computer-readable storage medium comprising instructions which, when executed by at least one processor, configure said at least one processor to carry out a method (40) according to any one of claims 21 to 28 or a method (50) according to any one of claims 31 to 36.

Images