WO2025202041A1

WO2025202041A1 - Efficient uplink resource allocation for an ambient-iot device based on a segmentation capability of the ambient-iot device

Info

Publication number: WO2025202041A1
Application number: PCT/EP2025/057740
Authority: WO
Inventors: Rikin SHAH; Andreas Andrae; Rajat PUSHKARNA
Original assignee: Continental Automotive Technologies GmbH
Current assignee: Aumovio Germany GmbH
Priority date: 2024-03-27
Filing date: 2025-03-21
Publication date: 2025-10-02
Anticipated expiration: 2026-09-27
Also published as: DE102024108780A1

Abstract

The present disclosure relates to methods and devices for enabling an efficient allocation of uplink resources to a user equipment, UE (20), which comprises a wireless device (25), such as an Ambient-IoT device, by considering an uplink data segmentation capability of the wireless device (25).

Description

EFFICIENT UPLINK RESOURCE ALLOCATION FOR AN AMBIENT-IOT DEVICE BASED ON A SEGMENTATION CAPABILITY OF THE AMBIENT-IOT DEVICE

Technical field

[0001] The present disclosure relates to wireless communication systems and relates more specifically to methods and devices for enabling an efficient allocation of uplink resources to a wireless device, for example a wireless device harvesting electrical energy, by considering an uplink data segmentation capability of the 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] Currently, a user equipment, UE, willing to obtain the allocation of uplink resources may rely on the buffer status reporting procedure defined in TS 38.321 V18.0.0. The buffer status reporting procedure (BSR) is used to provide the serving base station (gNB) with information about an uplink data volume present at the UE, that the UE would like to transmit to the gNB. This enables the gNB to make informed decisions regarding scheduling of uplink resources to efficiently manage the uplink data transmissions.

[0006] However, other constraints might limit the usage of uplink resources by an A-loT device, which constraints should be considered by the gNB to ensure that the allocated uplink resources can indeed be used by an A-loT device, to avoid wasting uplink resources.

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 enabling an efficient allocation of uplink resources to a wireless device, for example an A-loT device, by considering an uplink data segmentation capability of the wireless device.

[0008] Indeed, in the context of Ambient-loT, there is a possibility that some wireless devices will have no uplink data segmentation capability. A wireless device with no uplink data segmentation capability will not be able to decompose the uplink data it has to transmit into a plurality of uplink data packets. In other words, for a wireless device with no uplink data segmentation capability, all the available uplink data needs to be transmitted in a single uplink data packet. Hence, such a wireless device will not be able to use allocated uplink resources if the amount of allocated uplink resources is lower than the volume of available uplink data and these allocated uplink resources will be wasted.

[0009] For that purpose, it is proposed to introduce means enabling the radio access network, RAN, to determine whether a given wireless device supports uplink data segmentation. The allocation of uplink resources by the RAN can then be based on the uplink data segmentation capability of each wireless device and should try and ensure that the amount of uplink resources allocated to a wireless device with no uplink data segmentation capability is sufficient (or at least likely sufficient) to transmit all the uplink data available at the wireless device.

[0010] 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 a communication unit configured to exchange data with a radio access network, RAN, of the wireless communication system, wherein the method comprises: transmitting to the RAN an indication of an uplink data segmentation capability of the wireless device, receiving an allocation of uplink resources determined by the RAN based on the indicated uplink data segmentation capability.

[0011] 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.

[0012] In some embodiments, the method according to the first aspect comprises transmitting a buffer status report, BSR, which includes an indication of a volume of uplink data that the wireless device may have to transmit to the RAN, wherein the allocation of uplink resources to the wireless device is further determined by the RAN based on the BSR. [0013] In some embodiments of the method according to the first aspect, the BSR is a predicted BSR, PBSR, wherein the PBSR is transmitted before the wireless device has the uplink data to transmit to the RAN.

[0014] In some embodiments of the method according to the first aspect, the indication of the volume of uplink data that the wireless device may have to transmit corresponds to a maximum volume of uplink data that the wireless device may have to transmit in response to receiving an uplink transmission triggering signal from the RAN.

[0015] In some embodiments of the method according to the first aspect, the uplink transmission triggering signal is received without the wireless device transmitting a prior uplink resource allocation request to the RAN.

[0016] In some embodiments of the method according to the first aspect, the uplink transmission triggering signal is a wake-up signal from the RAN 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 from the RAN.

[0017] In some embodiments of the method according to the first aspect, the indication of the uplink data segmentation capability is transmitted in a user equipment, UE, capability message.

[0018] In some embodiments of the method according to the first aspect, the indication of the uplink data segmentation capability is provided as a single bit.

[0019] In some embodiments of the method according to the first aspect, 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.

[0020] 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.

[0021] 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.

[0022] 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 plurality of wireless devices wherein the method comprises: receiving from a wireless device an indication of an uplink data segmentation capability of said wireless device, determining an allocation of uplink resources to the wireless device based on the received indication of the uplink data segmentation capability of the wireless device.

[0023] 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.

[0024] In some embodiments, the method according to the fourth aspect comprises receiving from the wireless device a buffer status report, BSR, which includes an indication of a volume of uplink data that the wireless device may have to transmit to the BS, wherein the allocation of uplink resources to the wireless device is further determined based on the received BSR.

[0025] In some embodiments of the method according to the fourth aspect, the BSR is a predicted BSR, PBSR, wherein the PBSR is received before the wireless device has the uplink data to transmit to the RAN.

[0026] In some embodiments of the method according to the fourth aspect, the indication of the volume of uplink data that the wireless device may have to transmit corresponds to a maximum volume of uplink data that the wireless device may have to transmit in response to receiving an uplink transmission triggering signal from the BS.

[0027] In some embodiments of the method according to the fourth aspect, the uplink transmission triggering signal is received without the wireless device transmitting a prior uplink resource allocation request to the RAN.

[0028] In some embodiments of the method according to the fourth aspect, the uplink transmission triggering signal is a wake-up signal from the RAN 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 from the RAN.

[0029] In some embodiments of the method according to the fourth aspect, the indication of the uplink data segmentation capability is received in a user equipment, UE, capability message.

[0030] In some embodiments of the method according to the fourth aspect, the indication of the uplink data segmentation capability is provided as a single bit.

[0031] In some embodiments of the method according to the fourth aspect, 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.

[0032] 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.

[0033] 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.

[0034] According to a sixth 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.

[0035] According to a seventh 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.

[0036] According to an eighth 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 exchanging data according to any one of the embodiments of the present disclosure.

Brief description of figures

[0037] 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.

[0038] 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

[0039] The detailed description set forth below, with reference to the figures, is intended as a 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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. [0046] 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.

[0047] 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.

[0048] 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). [0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] In some examples, the electrical energy collected by the energy harvesting unit 254 may be provided directly to the other equipment of the wireless device 25, in which case the energy storage unit 255 is optional and needs not to be included in the wireless device. [0054] Figure 3 represents schematically an example of a BS 30 suitable to implement any method, discussed in the present disclosure, performed by the RAN.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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 specific energy 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.

[0059] As discussed above, the present disclosure aims at enabling an efficient allocation of uplink resources to a wireless device 25, by further considering constraints that may limit the usage of allocated uplink resources by some wireless devices 25. For example, there is a possibility that some wireless devices 25 have no uplink data segmentation capability. A wireless device with no uplink data segmentation capability will not be able to decompose the uplink data it has to transmit into a plurality of uplink data packets. In other words, for a wireless device with no uplink data segmentation capability, all the available uplink data needs to be transmitted in a single uplink data packet. Hence, such a wireless device will not be able to use allocated uplink resources if the amount of allocated uplink resources is lower than the volume of available uplink data and these uplink resources will be wasted.

[0060] Hence, it is proposed to introduce means enabling the RAN to determine whether a given wireless device 25 supports uplink data segmentation, to try and ensure that the amount of uplink resources allocated to a wireless device 25 is compatible with the uplink data segmentation capability of this wireless device 25.

[0061] We now present examples of signaling strategies that may be implemented to let the RAN determine the uplink data segmentation capability of a wireless device 25.

[0062] Explicit uplink data segmentation capability reporting [0063] 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.

[0064] As illustrated by figure 4, the method 40 for exchanging data comprises a step S40 of transmitting to the RAN an indication of an uplink data segmentation capability of the wireless device 25. In other words, the wireless device 25 explicitly notifies the RAN of whether it supports uplink data segmentation.

[0065] For example, the indication of the uplink data segmentation capability may be provided to the RAN as a single bit. For example, a bit value ‘1’ indicates that the wireless device 25 does not support uplink data segmentation, and a bit value ‘0’ indicates that the wireless device 25 supports uplink data segmentation. More generally, the uplink data segmentation capability indication may use any suitable format and the choice of a specific format consists in a specific but non-limitative embodiment of the present disclosure.

[0066] It should be noted that the uplink data segmentation capability indication may be transmitted 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. For example, the uplink data segmentation capability indication may be transmitted by the wireless device 25 in a UE capability message (radio resource control, RRC, message).

[0067] As illustrated by figure 4, the method 40 for exchanging uplink data comprises a step S41 of receiving an allocation of uplink resources that the wireless device 25 may use for transmitting uplink data. For example, the allocated uplink resources may be configured grant, CG, uplink resources or dynamic grant uplink resources.

[0068] As discussed above (and hereinbelow), the allocated uplink resources are determined by the RAN based on the received uplink data segmentation capability indication. In particular, the amount of uplink resources allocated to the wireless device 25 should be compatible with the uplink data segmentation capability of the wireless device 25. If the wireless device 25 supports uplink data segmentation, then there is no constraint on the amount of uplink resources that may be allocated. In turn, if the wireless device 25 does not support uplink data segmentation, then the RAN should try and ensure that the amount of uplink resources allocated to the wireless device 25 enables it to transmit all the available uplink data without segmentation. In other words, if the wireless device 25 does not support uplink data segmentation, the amount of uplink resources allocated should be equal to or greater than the volume of uplink data available at the wireless device 25 (since the uplink resources would otherwise be wasted as being unusable by the wireless device 25). [0069] Hence, at least when a wireless device 25 does not support uplink data segmentation, the RAN should be able to determine or estimate the volume of uplink data that the wireless device 25 may have to transmit in order to be able to allocate to this wireless device 25 a compatible amount of uplink resources.

[0070] In the example of figure 4, the method 40 for exchanging data comprises an optional step S42 of transmitting, by the wireless device 25, a BSR to the RAN.

[0071] As recalled above, the buffer status reporting procedure is defined in TS 38.321 V18.0.0 and the BSR is used to provide the serving base station 30 of the RAN with information about the volume of uplink data present at the wireless device 25, that the wireless device 25 would like to transmit to the RAN. In the present case, the BSR can be used by the RAN to ensure that the amount of uplink resources allocated to the wireless device 25 is sufficient to transmit the volume of uplink data indicated in the BSR without segmentation if the wireless device 25 has indicated that it does not support uplink data segmentation.

[0072] In some examples, the BSR may be a predicted BSR, PBSR. This PBSR represents a volume of uplink data that the wireless device 25 expects to transmit to the RAN in the future. By “predicted”, we mean that the PBSR corresponds to an a priori estimation of the volume of uplink data that the wireless device 25 may have to transmit during the next uplink data transmission, before the estimated volume of uplink data has actually arrived at the wireless device’s uplink data buffer(s).

[0073] The BSR procedure requires the wireless device 25 to trigger a random-access channel, RACH, procedure and/or a scheduling request, SR, procedure. This requires the exchange of several signaling messages between the wireless device 25 and the RAN. In turn, the RAN may trigger an uplink data transmission and directly allocate uplink resources to the wireless device 25, with an amount of uplink resources allocated determined based on the PBSR previously received from this wireless device 25, without having to exchange further signaling messages between the RAN and this wireless device 25.

[0074] For example, the PBSR is determined by the wireless device 25 based on at least one characteristic of uplink data to be transmitted by the wireless device 25.

[0075] For example, the at least one characteristic of the uplink data to be transmitted may comprise a traffic class (priority level, latency requirement, etc.) and/or a type of the wireless device 25 and/or a type of service running on the UE 20, etc. For example, based on the type of service running on the UE, the wireless device 25 may predict the volume of uplink data that it may have to transmit at each uplink data transmission.

[0076] Alternatively, or in combination therefor, the wireless device 25 may use an history of past uplink data transmissions to predict the volume of uplink data it may have to transmit during the next uplink data transmission. Alternatively, or in combination thereof, if the UE 20 generates periodically uplink data to be transmitted having a predetermined size, the wireless device 25 may predict the volume of uplink data that it may have to transmit during the next uplink transmission based on the approximate time gap between uplink data transmissions triggered by the RAN (which approximate time gap may be estimated, or previously agreed with the RAN, or it may be determined as the mean or maximum time gap observed between past uplink transmissions triggered by the RAN).

[0077] Any estimation method may be used for predicting the volume of uplink data that may be transmitted in the next uplink data transmission, and the choice of a specific method corresponds to a specific but non-limitative embodiment of the present disclosure.

[0078] In preferred embodiments, the PBSR transmitted by the wireless device 25 may be conservative if the wireless device 25 does not support uplink data segmentation, i.e. , the PBSR may correspond to a maximum volume of uplink data that the wireless device 25 may have to transmit during the next uplink data transmission. However, the PBSR may also correspond in other examples to e.g. a mean or minimum volume of uplink data that the wireless device 25 may have to transmit at each uplink transmission triggered by the RAN, in particular if the wireless device 25 supports uplink data segmentation.

[0079] It should be noted that the PBSR transmitted may correspond to a static configuration or to a dynamic configuration.

[0080] By “static configuration”, we mean that the PBSR remains valid for all subsequent uplink transmissions triggered by the RAN unless overwritten by a new static configuration transmitted by the same wireless device 25. With a static configuration, the PBSR needs not to be transmitted before each future uplink transmission triggered by the RAN and can even be transmitted only once to the RAN (or at least once per serving BS 30).

[0081] By “dynamic configuration”, we mean that the PBSR remains valid only for a predetermined number of subsequent uplink transmissions and may remain valid only for a single subsequent uplink transmission in some cases.

[0082] The PBSR may be transmitted 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.

[0083] For example, the signaling message with the PBSR may be transmitted shortly after an authentication of the wireless device 25 by the RAN. For example, the PBSR may be included (possibly with the uplink data segmentation capability indication) in a UE capability message sent by the wireless device 25. Including the PBSR in a UE capability message can be used for example for a static configuration of the PBSR.

[0084] According to another example, the wireless device 25 may transmit a PBSR during an ongoing uplink transmission, or at the end of an ongoing uplink transmission e.g. before the wireless device 25 transitions to a sleep mode. Such a PBSR, transmitted during or at the end of an ongoing uplink transmission, is to be used for the next uplink transmission triggered by the RAN. Such a PBSR transmission scheme can be used for example for a dynamic configuration of the PBSR, but also for a static configuration thereof if the transmitted PBSR is to remain valid for all subsequent uplink transmissions (unless overwritten by a new static configuration).

[0085] It should be noted that both approaches, static and dynamic configuration of the PBSR, can also be combined in some embodiments. For example, the wireless device 25 may transmit a static configuration of the PBSR, to be used by default, e.g., in a UE capability message. Subsequently, the wireless device 25 may transmit a dynamic configuration of the PBSR, e.g., during or at the end of an ongoing uplink transmission, which replaces temporarily the static configuration (e.g., for only a predetermined number of triggered uplink transmissions).

[0086] The PBSR 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. For example, the format of the PBSR may be based on the format of the BSR medium access control, MAC, control element, CE.

[0087] It should be noted that other methods may be used to enable the RAN to determine or estimate the volume of uplink data that a wireless device 25 with no uplink data segmentation capability may have to transmit in order to be able to allocate to this wireless device 25 a compatible amount of uplink resources.

[0088] For example, the RAN may estimate a PBSR for a wireless device 25 without requiring said wireless device 25 to transmit a PBSR. Basically, all that has been described previously for the determination of the PBSR by the wireless device 25 may also be applied on the RAN side. According to another example, the RAN may progressively learn a PBSR for a given wireless device 25 with no uplink data segmentation capability. For example, the RAN may iteratively increase the amount of uplink resources allocated to this wireless device 25 until the allocated uplink resources are successfully used by the wireless device 25 (implying that uplink resources are somehow sacrificed during the initial iterations of this learning phase). Hence, the amount of uplink resources allocated to the wireless device 25 during the last iteration was compatible with the volume of uplink data the wireless device 25 had to transmit (without segmentation). This amount of uplink resources allocated during the last iteration can then be used as PBSR for subsequent (initial) uplink resource allocations for this wireless device 25.

[0089] Generally, the uplink resources allocated to the wireless device 25 may be indicated to the wireless device 25 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.

[0090] In some examples, the allocated uplink resources may be indicated in an uplink transmission triggering signal transmitted by the RAN (in particular if the amount of uplink resources allocated is determined by the RAN based on a PBSR received from the wireless device 25 or estimated by the RAN). The purpose of the uplink transmission triggering signal is to indicate to the wireless device 25 that it can initiate an uplink data transmission on the uplink resources allocated to the wireless device 25.

[0091] 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.

[0092] 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.

[0093] As illustrated by figure 5, the method 50 for exchanging data comprises a step S50 of receiving from the wireless device 25 an indication of an uplink data segmentation capability of said wireless device 25 (transmitted by the wireless device 25 during step S40). As discussed above, the uplink data segmentation capability indication may be received e.g. with a UE capability message, and may consist in a single bit in some cases.

[0094] The method 50 for exchanging data comprises also a step S51 of determining an allocation of uplink resources to the wireless device 25 based on the received indication of the uplink data segmentation capability of the wireless device 25. All that has been said previously for the determination of the amount of uplink resources that should be allocated to a wireless device 25 based on its uplink data segmentation capability applies similarly.

[0095] In particular, if the wireless device 25 does not support uplink data segmentation, then the BS 30 should try and ensure that the amount of uplink resources allocated to the wireless device 25 enables it to transmit all the available uplink data without segmentation. [0096] For that purpose, at least when a wireless device 25 does not support uplink data segmentation, the BS 30 should be able to determine or estimate the volume of uplink data that the wireless device 25 may have to transmit in order to be able to allocate to this wireless device 25 a compatible amount of uplink resources.

[0097] In the example of figure 5, it is assumed in a non-limitative manner that the wireless device 25 transmits a BSR (or PBSR) to the BS 30 and the method 50 for exchanging data comprises an optional step S52 of receiving, by the BS 30, a (P)BSR from the wireless device 25, such that the allocation of uplink resources may be determined based on the received (P)BSR.

[0098] Generally, any method may be used for predicting the volume of uplink data that the wireless device 25 may have to transmit, and the choice of a specific method corresponds to a specific but non-limitative embodiment of the present disclosure. For example, as discussed above, the PBSR for a given wireless device 25 may be estimated unilaterally by the BS 30 in some cases, without requiring the wireless device 25 to transmit a PBSR.

[0099] As discussed above, an indication of the allocated uplink resources is transmitted by the BS 30 to the wireless device 25. Generally, the indication of the uplink resources allocated to the wireless device 25 may be indicated 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.

[0100] In some examples, the indication of the allocated uplink resources may be included in an uplink transmission triggering signal transmitted by the BS 30 to the wireless device 25. In some cases, the uplink transmission triggering signal may correspond to a wake-up signal that transitions the wireless device 25 from a sleep mode to an active mode or is a signaling message transmitted after transmitting a wake-up signal to the wireless device 25 (to transition the wireless device 25 to an active mode before transmitting the uplink transmission triggering signal).

[0101] 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.

[0102] Implicit uplink data segmentation capability determination

[0103] 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.

[0104] Basically, the examples illustrated by figures 6 and 7 are similar to those illustrated by figures 4 and 5, such that all that has been said previously in reference to figures 4 and 5 applies similarly to figures 6 and 7 unless explicitly stated otherwise. The only difference consists in how the BS 30 determines whether a given wireless device 25 supports uplink data segmentation. In the examples illustrated by figures 4 and 5, the wireless device 25 explicitly indicates to the BS 30 whether it supports uplink data segmentation. In turn, in the examples illustrated by figures 6 and 7, the BS 30 determines whether the wireless device 25 supports uplink data segmentation based on a type of the wireless device 25, among a plurality of different wireless device types, which type may be explicitly indicated by the wireless device 25 or may be determined otherwise by the BS 30.

[0105] For example, the type of the wireless device 25 may correspond to an A-loT device type. For example, section 4.3 of the technical report TR 38.848 V18.0.0 defines different types of A-loT devices, based mainly on electrical energy storage capability and independent signal generation/amplification capability. Currently, the technical report TR 38.848 V18.0.0 defines three different types, namely types A (no electrical energy storage, no independent signal generation/amplification), B (with electrical energy storage, no independent signal generation) and C (with electrical energy storage, with independent signal generation). However, more A-loT device types may be defined, for example as subtypes of the types B and C to define more precisely electrical energy storage capabilities. [0106] In the example illustrated by figure 6, it is considered in a non-limitative manner that the wireless device 25 explicitly indicates its type to the RAN, and the method 60 for exchanging data comprises a step S60 of transmitting to the RAN an indication of the type of the wireless device 25, among the plurality of possible different wireless device types.

[0107] For example, the indication of the wireless device type may be provided to the RAN as a bit vector. For example, the bit vector may consist in two bits and: a bit vector value ‘00’ indicates a type A Ambient-loT device, a bit vector value ‘0T indicates a type B Ambient-loT device, a bit vector value ‘10’ indicates a type C Ambient-loT device, a bit vector value ‘1 T may be reserved for future use (for example for a type D Ambient-loT device).

[0108] Of course, a different number of bits may be considered for the bit vector, depending on the number of different wireless device types. Also, any suitable format may be used for indicating the wireless device type, and the choice of a specific format corresponds to a specific but non-limitative embodiment of the present disclosure.

[0109] It should be noted that the wireless device type may be transmitted 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. For example, the wireless device type may be transmitted by the wireless device 25 in a UE capability message.

[0110] It is assumed that the RAN can determine whether a wireless device 25 supports uplink data segmentation based on its wireless device type. For example, the RAN may use a predetermined mapping between the plurality of different wireless device types and respective uplink data segmentation capabilities, as will be discussed hereinbelow.

[0111] As illustrated by figure 6, the method 60 for exchanging data comprises a step S61 of receiving an allocation of uplink resources. For example, the allocated uplink resources may be CG uplink resources or dynamic grant uplink resources.

[0112] As discussed above in relation with figures 4 and 5, the allocation of uplink resources is determined by the RAN based on the uplink data segmentation capability of the wireless device 25 (which is determined in the present case base on the wireless device’s type). Also, the allocation of uplink resources may be received in any suitable signaling message, as discussed previously. For example, the allocation of uplink resources may be received in an uplink transmission triggering signal.

[0113] All that has been said previously in relation to the determination of the allocation of uplink resources based on the uplink data segmentation capability of a wireless device 25 applies similarly to the examples in figures 6 and 7. In the example illustrated by figure 6, it is assumed in a non-limitative manner that the determination of the allocation of uplink resources further uses a BSR or PBSR transmitted by the wireless device 25, and the method 60 for exchanging data comprises an optional step S62 of transmitting a (P)BSR to the RAN.

[0114] 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.

[0115] As illustrated by figure 7, the method 70 for exchanging data comprises a step S70 of determining a type of the wireless device 25 among the plurality of different wireless device types. As discussed above, the step S70 may consist in the BS 30 receiving an explicit indication of the wireless device type from the wireless device 25 (step S60 in figure 6). However, it is also possible, in other examples, to determine the wireless device’s type without requiring the wireless device 25 to transmit such an indication. According to a non- limitative example, the respective types of a plurality of wireless devices 25 may be stored in a database. In such a case, the BS 30 may retrieve from the database a type of a given wireless device 25 based, e.g., on an identifier of said given wireless device 25.

[0116] As illustrated by figure 7, the method 70 for exchanging data comprises a step S71 of determining an uplink data segmentation capability of the wireless device 25, based on the determined type of said wireless device 25. For example, the BS 30 may use a predetermined mapping between the plurality of different wireless device types and respective uplink data segmentation capabilities. For example, the mapping between the plurality of different wireless device types and the respective uplink data segmentation capabilities may be predefined (e.g., specified by a standard).

[0117] Table 1 represents a non-limitative example of mapping between the plurality of different wireless device types and the respective uplink data segmentation capabilities. In this example, 4 (four) different wireless device types are considered in a non-limitative manner, for example types A, B, C and D discussed above. Of course, it is possible to consider a different number of wireless device types in other examples.

Table 1

[0118] In the example of Table 1, if the determined wireless device type corresponds to type A or B, then the BS 30 considers that the corresponding wireless device 25 does not support uplink data segmentation, and the allocation of uplink resources should take this absence of uplink data segmentation support into account. In turn, if the determined wireless device type corresponds to type C or D, then the BS 30 considers that the corresponding wireless device 25 supports uplink data segmentation.

[0119] The method 70 for exchanging data comprises also a step S72 of determining an allocation of uplink resources to the wireless device 25 based on the uplink data segmentation capability determined for the wireless device 25. All that has been said previously for the determination of the amount of uplink resources that should be allocated to a wireless device 25 based on its uplink data segmentation capability applies similarly.

[0120] In particular, if the wireless device 25 does not support uplink data segmentation, then the BS 30 should try and ensure that the amount of uplink resources allocated to the wireless device 25 enables it to transmit all the available uplink data without segmentation. [0121] For that purpose, at least when a wireless device 25 does not support uplink data segmentation, the BS 30 should be able to determine or estimate the volume of uplink data that the wireless device 25 may have to transmit in order to be able to allocate to this wireless device 25 a compatible amount of uplink resources.

[0122] In the example of figure 7, it is assumed in a non-limitative manner that the wireless device 25 transmits a BSR (or PBSR) to the BS 30 and the method 70 for exchanging data comprises an optional step S73 of receiving, by the BS 30, a (P)BSR from the wireless device 25, such that the allocation of uplink resources may be determined based on the received (P)BSR.

[0123] Generally, any method may be used for predicting the volume of uplink data that the wireless device 25 may have to transmit, and the choice of a specific method corresponds to a specific but non-limitative embodiment of the present disclosure. For example, as discussed above, the PBSR for a given wireless device 25 may be estimated unilaterally by the BS 30 in some cases, without requiring the wireless device 25 to transmit a PBSR.

[0124] As discussed above, an indication of the allocated uplink resources is transmitted by the BS 30 to the wireless device 25. Generally, the indication of the uplink resources allocated to the wireless device 25 may be indicated 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.

[0125] In some examples, the indication of the allocated uplink resources may be included in an uplink transmission triggering signal transmitted by the BS 30 to the wireless device 25. In some cases, the uplink transmission triggering signal may correspond to a wake-up signal that transitions the wireless device 25 from a sleep mode to an active mode or is a signaling message transmitted after transmitting a wake-up signal to the wireless device 25. [0126] 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.

[0127] 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.

[0128] 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). The present disclosure may also be applied with wireless devices 25 which do not comprise an energy storage unit, and which operate only with an energy harvesting unit 254 which provides the collected electrical energy directly to the other equipment of the wireless device 25.

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, wherein the wireless device comprises a communication unit (253) configured to exchange data with a radio access network, RAN, of the wireless communication system, wherein the method comprises:

(540) transmitting to the RAN an indication of an uplink data segmentation capability of the wireless device,

(541) receiving an allocation of uplink resources determined by the RAN based on the indicated uplink data segmentation capability.

2. The method (40) according to claim 1 , comprising (S42) transmitting a buffer status report, BSR, which includes an indication of a volume of uplink data that the wireless device may have to transmit to the RAN, wherein the allocation of uplink resources to the wireless device is further determined by the RAN based on the BSR.

3. The method (40) according to claim 2, wherein the BSR is a predicted BSR, PBSR, wherein the PBSR is transmitted before the wireless device has the uplink data to transmit to the RAN.

4. The method (40) according to claim 3, wherein the indication of the volume of uplink data that the wireless device may have to transmit corresponds to a maximum volume of uplink data that the wireless device may have to transmit in response to receiving an uplink transmission triggering signal from the RAN.

5. The method (40) according to any one of the preceding claims, wherein the indication of the uplink data segmentation capability is transmitted in a user equipment, UE, capability message.

6. The method (40) according to any one of the preceding claims, wherein the indication of the uplink data segmentation capability is provided as a single bit.

7. The method (40) according to any one of the preceding claims, 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.

8. 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 the preceding claims.

9. A user equipment, UE (20), comprising a wireless device according to claim 8.

10. 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 plurality of wireless devices (25), wherein the method comprises:

(550) receiving from a wireless device an indication of an uplink data segmentation capability of said wireless device,

(551) determining an allocation of uplink resources to the wireless device based on the received indication of the uplink data segmentation capability of the wireless device.

11. The method (50) according to claim 10, comprising (S52) receiving from the wireless device a buffer status report, BSR, which includes an indication of a volume of uplink data that the wireless device may have to transmit to the BS, wherein the allocation of uplink resources to the wireless device is further determined based on the received BSR.

12. The method (50) according to claim 11 , wherein the BSR is a predicted BSR, PBSR, wherein the PBSR is received before the wireless device has the uplink data to transmit to the RAN.

13. The method (50) according to claim 12, wherein the indication of the volume of uplink data that the wireless device may have to transmit corresponds to a maximum volume of uplink data that the wireless device may have to transmit in response to receiving an uplink transmission triggering signal from the BS.

14. The method (50) according to any one of claims 10 to 13, wherein the indication of the uplink data segmentation capability is received in a user equipment, UE, capability message.

15. The method (50) according to any one of claims 10 to 14, wherein the indication of the uplink data segmentation capability is provided as a single bit.

16. The method (50) according to any one of claims 10 to 15, 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.

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 10 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 9.

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 (40) according to any one of claims 1 to 7 or a method (50) according to any one of claims 10 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 (40) according to any one of claims 1 to 7 or a method (50) according to any one of claims 10 to 16.