WO2025172799A1

WO2025172799A1 - Terminal device communication

Info

Publication number: WO2025172799A1
Application number: PCT/IB2025/051274
Authority: WO
Inventors: Muhammad Majid BUTT
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2024-02-13
Filing date: 2025-02-06
Publication date: 2025-08-21
Anticipated expiration: 2026-08-13
Also published as: GB2638161A; GB202401980D0

Abstract

A method, apparatus and computer program is described comprising: obtaining information, said information being associated with one or more transmissions from a terminal device, said terminal device comprising: means for transmitting data in first and second modes, wherein, in the first mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; selecting, based at least in part on said information, a mode of the first and second modes; and providing to said terminal device an instruction to operate in the selected mode for one or more transmissions.

Description

TERMINAL DEVICE COMMUNICATION

Field

Example embodiments may relate to systems, methods and/or computer programs relating to terminal device communications.

Background

There remains a need to enable efficient communications between network devices and terminal devices.

Summary

The scope of protection sought for various embodiments of the invention is set out by the independent claims. The embodiments and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the invention.

According to a first aspect, there is provided an apparatus (e.g. a network node), comprising: means for obtaining information, said information being associated with one or more transmissions from a terminal device, said terminal device comprising: means for transmitting data in first and second modes, wherein, in the first mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; means for selecting, based at least in part on said information, a mode of the first and second modes; and means for providing to said terminal device an instruction to operate in the selected mode for one or more transmissions.

Some example embodiments further comprise means for providing a query to the terminal device, wherein the information comprises a response to said query, and wherein the means for selecting a mode of the first and second modes selects the mode based at least in part on said response. Moreover, some example embodiments further comprise means for providing to the terminal device before providing the query a second instruction, said second instruction being an instruction to operate in the first mode. The query may comprise an activation signal for backscattering by the terminal device, wherein said terminal device is configured to modulate the response to said query on the backscattered signal.

In some example embodiments, said response comprises data indicating whether an amount of energy stored by the terminal device is above a first threshold, and wherein said means for selecting selects the second mode if the data indicates that an amount of energy stored is above said first threshold.

In some example embodiments, said response comprises data indicating whether an amount of energy stored by the terminal device is above a/the first threshold, and wherein said means for selecting selects the first mode or the second mode if the data indicates that an amount of energy stored is below said first threshold.

Some example embodiments, further comprise means for determining an amount of time that has elapsed since the receipt of a previous transmission by said terminal device, and wherein the means for providing said query provides said query in response to the determined amount of elapsed time exceeding a timer threshold.

The response may comprise data indicating whether the terminal device has data to transmit, and wherein the apparatus further comprises: means for resetting a determined time that has elapsed since the receipt of a previous transmission, if said response indicates that the terminal device does not have data to transmit.

In some example embodiments, the information comprises a request, and wherein the means for selecting a mode of the first and second modes selects the mode based at least in part on said request. The request may be a request to operate in the first mode. Moreover, the request may further include at least one of an amount of data to be transmitted by the terminal device, or a target latency.

In some example embodiments, said means for selecting selects the first or the second mode based on at least one of an amount of data buffered at the terminal device, a target latency, a distance between the apparatus and the terminal device, or a determination of whether to provide an activation signal to the terminal device.

Some example embodiments further comprise means for receiving from the terminal device an indication that the terminal device is to switch from the first mode to the second mode.

According to a second aspect, there is provided an apparatus (e.g. a terminal device) comprising: means for transmitting data in first and second modes, wherein, in the first mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; means for transmitting information to a network device using said means for transmitting data; means for receiving an instruction from said network device to operate in one of the first and second modes for one or more transmissions; and means for setting the mode in which the data transmitting means operates to the instructed mode.

Some example embodiments further comprise means for receiving a query from the network device, wherein the means for transmitting information is configured to transmit a response to said query. Moreover, some example embodiments further comprise means for receiving a second instruction before receiving the query, said second instruction being an instruction to switch the mode in which the means for transmitting data operates to the first mode, and wherein the means for transmitting data are configured to operate in the first mode in response to the receipt of said second instruction. Transmitting the response to said query may comprise modulating the response on a backscattered transmission. Some example embodiments further comprise means for determining whether an amount of energy stored by the apparatus is above a threshold, and wherein the response comprises information indicating whether said amount of energy stored is above said threshold.

Some example embodiments further comprise means for determining whether the apparatus has data for transmission to the network device, and wherein the response comprises information indicating whether the apparatus has data for transmission.

Some example embodiments further comprise means for determining that an amount of energy stored by said apparatus is below a first threshold and that the apparatus has data for transmission to said network device, and wherein, in response to making said determination, the means for transmitting information is configured to transmit a request to change the mode in which the means for transmitting data operates to the first mode. Moreover, some example embodiments further comprise means for determining an amount of data for transmission and/or a target latency for the data for transmission, and wherein the request to change mode includes an indication of said amount of data for transmission and/or the target latency.

Some example embodiments further comprise means for transmitting to the network device an indication that the apparatus is to switch from the first mode to the second mode. Moreover, some example embodiments further comprise means for determining that an amount of energy stored by said apparatus is above a second threshold, wherein the means for transmitting to the network device an indication that the apparatus is to switch from the first mode to the second mode are configured to transmit said indication in response to making said determination.

According to a third aspect, there is provided a method comprising: obtaining information, said information being associated with one or more transmissions from a terminal device, said terminal device comprising: means for transmitting data in first and second modes, wherein, in the first mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; selecting, based at least in part on said information, a mode of the first and second modes; and providing to said terminal device an instruction to operate in the selected mode for one or more transmissions.

The method may comprise providing a query to the terminal device, wherein the information comprises a response to said query, and wherein the selecting a mode of the first and second modes selects the mode based at least in part on said response. Moreover, some example embodiments further comprise providing to the terminal device before providing the query a second instruction, said second instruction being an instruction to operate in the first mode. The query may comprise an activation signal for backscattering by the terminal device, wherein said terminal device is configured to modulate the response to said query on the backscattered signal.

In some example embodiments, said response comprises data indicating whether an amount of energy stored by the terminal device is above a first threshold, and wherein said selecting selects the second mode if the data indicates that an amount of energy stored is above said first threshold.

In some example embodiments, said response comprises data indicating whether an amount of energy stored by the terminal device is above a/the first threshold, and wherein said selecting selects the first mode or the second mode if the data indicates that an amount of energy stored is below said first threshold.

Some example embodiments further comprise determining an amount of time that has elapsed since the receipt of a previous transmission by said terminal device, and wherein said query is provided in response to the determined amount of elapsed time exceeding a timer threshold. The response may comprise data indicating whether the terminal device has data to transmit. The method may comprise resetting a determined time that has elapsed since the receipt of a previous transmission, if said response indicates that the terminal device does not have data to transmit.

In some example embodiments, the information comprises a request. Selecting a mode of the first and second modes may comprising selecting the mode based at least in part on said request. The request may be a request to operate in the first mode. Moreover, the request may further include at least one of an amount of data to be transmitted by the terminal device, or a target latency.

In some example embodiments, selecting the first or the second mode is based on at least one of an amount of data buffered at the terminal device, a target latency, a distance between the apparatus and the terminal device, or a determination of whether to provide an activation signal to the terminal device.

Some example embodiments further comprise receiving from the terminal device an indication that the terminal device is to switch from the first mode to the second mode.

According to a fourth aspect, there is provided a method comprising: transmitting information to a network device using a means for transmitting data, wherein said means for transmitting data is configured to transmit data in first and second modes, wherein, in the first mode, transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; receiving an instruction from said network device to operate in one of the first and second modes for one or more transmissions; and setting the mode in which the data transmitting means operates to the instructed mode.

Some example embodiments further comprise receiving a query from the network device, wherein said information is transmitted in response to said query. Moreover, some example embodiments further comprise receiving a second instruction before receiving the query, said second instruction being an instruction to switch the mode in which the means for transmitting data operates to the first mode. Transmitting the response to said query may comprise modulating the response on a backscattered transmission.

Some example embodiments further comprise determining whether an amount of energy stored by the apparatus is above a threshold, and wherein the response comprises information indicating whether said amount of energy stored is above said threshold.

Some example embodiments further comprise determining that an amount of energy stored by said apparatus is below a first threshold and that there is data for transmission to said network device, and wherein, in response to making said determination, a request to change the mode is transmitted in the first mode. Moreover, some example embodiments further comprise determining an amount of data for transmission and/or a target latency for the data for transmission, and wherein the request to change mode includes an indication of said amount of data for transmission and/or the target latency.

Some example embodiments further comprise transmitting to the network device an indication that an apparatus is to switch from the first mode to the second mode. Moreover, some example embodiments further comprise determining that an amount of energy stored by said apparatus is above a second threshold, wherein an indication that the apparatus is to switch from the first mode to the second mode are configured to transmit said indication in response to making said determination.

According to a fifth aspect, there is provided an apparatus comprising (at least) a receiver (or some other means) for obtaining information, said information being associated with one or more transmissions from a terminal device, said terminal device comprising: means for transmitting data in first and second modes, wherein, in the first mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; a controller (or some other means) for selecting, based at least in part on said information, a mode of the first and second modes; and a transmitter (or some other means) for providing to said terminal device an instruction to operate in the selected mode for one or more transmissions.

According to a sixth aspect, there is provided an apparatus comprising (at least) a transmitter (or some other means) for transmitting information to a network device using a means for transmitting data, wherein said means for transmitting data is configured to transmit data in first and second modes, wherein, in the first mode, transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; a receiver (or some other means) for receiving an instruction from said network device to operate in one of the first and second modes for one or more transmissions; and a controller (or some other means) setting the mode in which the data transmitting means operates to the instructed mode.

According to a seventh aspect, there is provided a network device comprising: means for receiving a request from an energy harvesting device, said energy harvesting device comprising means for transmitting data in active and backscattering modes, wherein, in the backscattering mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the active mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; means for selecting, based at least in part on said request, a mode of the backscattering and active modes; and means for providing to said energy harvesting device an instruction to operate in the selected mode for one or more transmissions.

According to an eighth aspect, there is provided an energy harvesting device comprising: means for transmitting data in active and backscattering modes, wherein, in the backscattering mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the active mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; means for transmitting to said network device a request, using the means for transmitting data, to change the mode in which the means for transmitting data operates; means for receiving an instruction from said network device to operate in one of the backscattering and active modes for one or more transmissions; and means for setting the mode in which the data transmitting means operates to the instructed mode.

According to a ninth aspect, there is provided a method comprising: receiving a request from an energy harvesting device, said energy harvesting device comprising means for transmitting data in active and backscattering modes, wherein, in a backscattering mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in an active mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; selecting, based at least in part on said request, a mode of the backscattering and active modes; and providing to said energy harvesting device an instruction to operate in the selected mode for one or more transmissions.

According to a tenth aspect, there is provided a method comprising: transmitting, by an energy harvesting device, for receipt by a network device, a request, said energy harvesting device comprising means for transmitting data in active and backscattering modes, wherein, in the backscattering mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the active mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated, wherein said request is a request to change the mode in which the means for transmitting data operates; receiving an instruction from said network device to operate in a mode of the backscattering and active modes for one or more transmissions; and setting the mode in which the data transmitting means operates to the instructed mode.

According to an eleventh aspect, there is provided a network device (e.g. a network node), comprising : means for providing a query to an energy harvesting device, said energy harvesting device comprising: means for transmitting data in active and backscattering modes, wherein, in the backscattering mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the active mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; means for obtaining a response to said query from said energy harvesting device; means for selecting, based at least in part on said response, one of the active mode or the backscattering mode; and means for providing to said energy harvesting device an instruction to operate in the selected mode for one or more transmissions.

According to a twelfth aspect, there is provided an energy harvesting device comprising: means for transmitting data in active and backscattering modes, wherein, in the backscattering mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the active mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; means for receiving a query from a network device; means for transmitting a response to said query to the network device using said means for transmitting data; means for receiving an instruction from said network device to operate in one of the backscattering and active modes for one or more transmissions; and means for setting the mode in which the data transmitting means operates to the instructed mode.

According to a thirteenth aspect, there is provided a method comprising: providing a query to an energy harvesting device, said energy harvesting device comprising: means for transmitting data in active and backscattering modes, wherein, in the backscattering mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the active mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; obtaining a response to said query from said energy harvesting device; selecting, based at least in part on said response, one of the active mode and the backscattering mode; and providing to said energy harvesting device an instruction to operate in the selected mode for one or more transmissions.

According to a fourteenth aspect, there is provided a method comprising: receiving a query from a network device at an energy harvesting device, said energy harvesting device comprising means for transmitting data in active and backscattering modes, wherein, in the backscattering mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the active mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; transmitting a response to said query to said network device using said means for transmitting data; receiving an instruction from said network device to operate in one of the backscattering and active modes for one or more transmissions; and setting the mode in which the data transmitting means operates to the instructed mode.

According to a fifteenth aspect, there is provided a computer-readable instructions which, when executed by a computing apparatus, cause the computing apparatus to perform (at least) any method as described herein (including the methods of the third, fourth, ninth, tenth, thirteenth and fourteenth aspects described above).

According to a sixteenth aspect, there is provided a computer-readable medium (such as a non-transitory computer-readable medium) comprising program instructions stored thereon for performing (at least) any method as described herein (including the methods of the third, fourth, ninth, tenth, thirteenth and fourteenth aspects described above).

According to a seventeenth aspect, there is provide an apparatus comprising: at least one processor; and at least one memory storing instructions which, when executed by the at least one processor, causes the apparatus to perform (at least) any method as described herein (including the methods of the third, fourth, ninth, tenth, thirteenth and fourteenth aspects described above).

Brief Description of the Drawings

Example embodiments will now be described by way of non-limiting example, with reference to the accompanying drawings, in which:

FIG. 1 is a block diagram of an apparatus in accordance with an example embodiment.

FIG. 2 is a block diagram of a device in accordance with an example embodiment; FIGS. 3 and 4 are flow charts showing methods in accordance with example embodiments;

FIGS. 5 and 6 are block diagrams of devices in accordance with example embodiments;

FIG. 7 is a schematic diagram of a scenario in accordance with an example embodiment;

FIGS. 8 to 10 are signalling diagrams of methods in accordance with example embodiments;

FIGS. 11 to 14 are flow charts showing methods in accordance with example embodiments;

FIG. 15 is a block diagram of components of a system in accordance with an example embodiment; and

FIG. 16 shows an example of tangible media for storing computer-readable code which when run by a computer may perform methods according to example embodiments described above.

Detailed Description

The scope of protection sought for various embodiments of the disclosure is set out by the independent claims. The embodiments and features, if any, described in the specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the disclosure.

In the description and drawings, like reference numerals refer to like elements throughout.

Energy harvesting devices are devices that are able to harvest energy, typically wirelessly, for example from sources of electromagnetic radiation. For example, energy harvesting devices may harvest energy from one or more sources that might include: solar energy or visible light using a solar panel, radio waves, or vibrations.

In some cases, energy harvesting devices may harvest energy from radio waves generated by non-3GPP sources, such as radio waves used in the transmission of terrestrial television. Alternatively, or in addition, energy harvesting devices may harvest energy from radio waves generated by 3GPP sources, such as UEs or gNBs.

A device based on energy harvesting may, for example, operate in an active mode or a passive mode. The device itself uses energy harvested from wireless radio waves or any other form of energy that can be harvested in its particular deployment scenario and may be expected to operate with ultra-low power in the range from one microwatt to hundreds of microwatts. For example, if energy is harvested from wireless radio waves, the output power of an energy harvester might range from several micro-watts to tens of micro-watts. If a solar panel is used for energy harvesting from sunlight, the output power might be less than 1 milli-watt due to the small size of the solar panel.

An energy harvesting device can harvest energy and then use an active circuit to transmit like a conventional transmitter. Some energy harvesting devices, typically called Passive devices or tags, do not possess active transmission circuitry, and use backscattering to transmit data.

Radio frequency identification (RFID) solutions may rely on backscattering technology. Such RFID solutions may be enhanced, and new solutions may be developed through the application of 3GPP technologies. In particular, coverage may be enhanced, energy harvesting from a dedicated or ambient energy source may be introduced, and energy may be consumed more efficiently.

Devices implementing backscattering technology may be battery-less devices or devices with limited energy storage capabilities, and the energy can be provided by harvesting radio waves, visible light, other electromagnetic radiation, motion, etc.

Such devices may be suitable for operation as part of an internet of things (loT). In some examples, an internet of things device that relies in part on harvested ambient energy may be referred to as an ambient internet of things (AIoT). Ambient loTs may be used in various industries, including logistics, manufacturing, transportation, energy, etc.

Devices capable of harvesting energy wirelessly and communicating wirelessly have advantages, for example in applications in which running wires and/or regularly replacing batteries is impractical. For example, in manufacturing or logistics, providing wired devices or devices having large batteries may be cost prohibitive if a large number of devices is to be used, or if articles to which the devices are to be affixed must be lightweight and/or portable. Moreover, if a device, such as a sensor, may be subjected to extreme environmental conditions, such as high pressure, extremely high/low temperatures, humidity, vibration, etc., then energy harvesting may be more practical than providing a wired connection or regularly replacing a battery.

Methods of communication by passive devices are provided. For example, as discussed in detail below, it is possible for some devices, upon receiving a suitable activation signal, to modulate data into the backscattering signal. The source of said activation signal may be the intended recipient of the data modulated into the backscattered signal, or the source may be some other device.

Devices capable of the aforementioned energy harvesting may, for example, be referred to as devices of an ambient internet of things (AIoT). Three types of AIoT devices have been proposed in 3GPP:

- Type A: No energy storage, no independent signal generation/amplification, i.e., backscattering transmission.

- Type B: Has energy storage, no independent signal generation, i.e., backscattering transmission. Use of stored energy can include amplification for reflected signals.

- Type C: Has energy storage, has independent signal generation, i.e., active RF components for transmission.

Devices of types A and B typically cannot contact the network without receiving an activation signal, while device type C typically cannot contact the network if it has insufficient energy. Disadvantages of each device type may be offset by providing a hybrid device that may operate using backscattering transmission under some circumstances and may operate by generating signals using active RF components under other circumstances.

It may be advantageous to use type C if there is enough harvested energy available (particularly from non-3GPP source), as there is no dependency on activation signals from 3GPP source. If there is enough energy available, a larger range can be achieved with type C transmission.

However, if there is not enough energy available, backscattering mode transmission may be preferable to collect small amount of data from the device.

In a hybrid transceiver, both Device type B (backscattering) and type C (active transmission) modes are available for transmission. Depending on different considerations, a particular mode can be selected.

Figure 1 is a block diagram of apparatus 10 according to an example embodiment of the invention. Apparatus 10 may be a network device. Apparatus 10 comprises transmitter 12, controller 14, and receiver 16. Receiver 16 is capable of obtaining information from one or more devices. In some example embodiments these may be terminal devices, hybrid energy harvesting devices, or other devices described herein. The said obtaining information from the devices may include indirect methods of transmission (e.g., in said obtaining information, information may be transmitted by an initial device to another intermediate device for transmission to the apparatus 10).

Transmitter 12 is capable of providing information to one or more devices. The said information may include instructions. The said providing information may include indirect methods of transmission (e.g., in said providing information, information may be transmitted by apparatus 10 to another device for transmission to a recipient device).

Controller 14 is in communication with transmitter 12 and receiver 16 such that received information may be processed and information for transmission may be determined by controller 14. Controller 14 may comprise a single physical component or a plurality of connected components.

In some example embodiments transmitter 12 and receiver 16 may together be embodied by a transceiver. A portion of the components for transmitting and receiving may be shared in said transceiver (e.g., an antenna may be shared).

Figure 2 is a block diagram of device 110 according to an example embodiment of the invention. Device 110 may be a terminal device. Device 110 comprises transmitter 112, controller 114, and receiver 116.

Transmitter 112 is capable of transmitting data and may be used to transmit information to a network device. The said providing information may include indirect methods of transmission (e.g., in said providing information, information may be transmitted by device 110 to another device for transmission by another device to a recipient device). Transmitter 112 is capable of operating in two modes. In the first mode, transmitting data comprises modulating said data on a backscattered signal. In the second mode, transmitting data comprises actively generating and transmitting a signal on which said data is modulated. The first and second modes may rely on separate components, or at least a portion of the components used in transmitting in the first and second modes (e.g., the antenna) may be shared.

Receiver 116 is capable of obtaining information from a network device (such as the device 10). In some example embodiments the network device is a gNB node, or another 3GPP network device. Said obtaining information from a network device may include obtaining information through indirect methods of transmission (e.g., in said obtaining information, information may be transmitted by an initial device to another device for transmission to device 110)

Controller 114 is in communication with transmitter 112 and receiver 116 such that received information may be processed and information for transmission may be determined by controller 114. Controller 114 may comprise a single physical component or a plurality of connected components.

Device 110 may generate or otherwise obtain data for communication to a network. Said data may accumulate in a buffer in a memory within or accessible to controller 14 of device 10.

In some example embodiments transmitter 112 and receiver 116 may together be embodied by a transceiver. A portion of the components for transmitting and receiving may be shared in said transceiver (e.g., an antenna may be shared).

Figure 3 is a flow diagram of a method 300 according to an example embodiment of the invention. Method 300 may be carried out by apparatus 10.

At step 310, information associated with one or more transmissions from a terminal device is obtained. Said terminal device is capable of transmitting data in two modes, and may be a device such as device 110 in some example embodiments. In the first mode transmitting data comprises modulating said data on a backscattered signal. In the second mode, transmitting data comprises actively generating and transmitting a signal on which said data is modulated. In some embodiments receiver 16 of apparatus 10 obtains said information.

At step 312 apparatus 10 selects a mode of the first and second modes based on the information obtained at step 310. This selecting may be performed by controller 14.

In some example embodiments, the received information comprises a response to a query sent by apparatus 10 to a device 110, and the mode is selected based at least in part upon said response.

Apparatus 10 may provide to device 110 a second instruction before providing the query, said second instruction being an instruction to operate in the first mode.

The query may comprise an activation signal for backscattering by device 110, and device 110 may modulate the response to the query on the backscattered signal.

The response may comprise data indicating whether an amount of energy stored by device 110 is above a first threshold, and the second mode may be selected if the data indicates that an amount of energy stored is above said first threshold.

The response may comprise data indicating whether an amount of energy stored by the terminal device is above a first threshold, and said selecting may select the first mode or the second mode if the data indicates that an amount of energy stored is below said first threshold.

Apparatus 10 may comprise means (such as a timer) for determining an amount of time that has elapsed since the receipt of a previous transmission by device 110, and said query may be provided in response to the determined amount of elapsed time exceeding a timer threshold.

The response may comprise data indicating whether the terminal device has data to transmit, and apparatus 10 may reset a determined time that has elapsed since the receipt of a previous transmission if said response indicates that the terminal device does not have data to transmit.

In some example embodiments the received information comprises a request from device 110, and the mode selected is based at least in part upon said request.

The request may be a request to operate in the first mode.

The request may further include at least one of an amount of data to be transmitted by the terminal device, or a target latency.

The first or second mode may be selected based on at least one of an amount of data buffered at the terminal device, a target latency, a distance between the apparatus and the terminal device, or a determination of whether to provide an activation signal to the terminal device. Apparatus 10 may receive from device 110 an indication that device 110 is to switch from the first mode to the second mode.

In some example embodiments, the received information comprises an indication of whether an amount of energy stored by device 110 is above or below a first threshold. If the received information comprises a response to a query, this response may comprise said indication. If the received information comprises a request to change modes, said request may comprise said indication.

As part of step 312, the controller 14 may determine that an amount of energy stored by device 110 is above the first threshold and may select the second mode in response.

As part of step 312, the controller 14 may determine that an amount of energy stored by device 110 is below the first threshold and may select one of the first and second mode in response. In this case, the selected mode may further be based on one or more of a distance between apparatus 10 and device 110, a latency requirement associated with data for transmission, or a size of the data for transmission, and the relative positions and capabilities of one or more other devices within the network.

At step 314 apparatus 10 provides the terminal device with an instruction to operate in the selected mode for one or more transmissions.

In some example embodiments, this instruction is an instruction to operate in the selected mode for an unspecified number of transmissions (e.g., until otherwise instructed, until an amount of stored energy exceeds a threshold, until device 110 has not received an activation signal for a particular period, or until some other condition is met). In other example embodiments, this instruction is an instruction to operate in the selected mode for one operation (one transmission), or another number of operations.

Figure 4 is a flow diagram of a method 400 according to an example embodiment of the invention. Method 400 may be carried out by an apparatus such as device no.

At step 410 device 110 transmits information to a network device (which may in some examples be apparatus 10) using transmitter 112.

In some example embodiments the transmitted information comprises a request from device 110 to change modes. In other example embodiments, the transmitted information comprises a response to a query sent from apparatus 10 to a device 110.

At step 412 device 110 receives an instruction from apparatus 10 to operate in a mode of the first and second modes.

At step 414 device 110 sets the mode in which the transmission means operates to the selected mode.

In some example embodiments, device 110 receives a query from apparatus 10, and the transmitted information comprises a response to said query, and the mode is selected based at least in part upon said response.

Device 110 may receive a second instruction before receiving the query, said second instruction being an instruction to switch the mode in which the transmitter 112 operates to the first mode, and transmitter 112 may operate in the first mode in response to the receipt of said second instruction.

Transmitting the response to said query may comprise modulating the response on a backscattered transmission.

Device 110 may comprise means for determining whether an amount of energy stored by device 110 is above a threshold, and the response may comprise information indicating whether said amount of energy stored is above said threshold.

The response may comprise indication indicating whether device 110 has data for transmission.

Device 110 may comprise means for determining whether an amount of energy stored by device 110 is below a first threshold and that device 110 has data for transmission to apparatus 10, and in response to making said determination, the transmitter 112 transmit a request to change the mode in which the transmitter 112 is operating to the first mode.

Device 110 may determine an amount of data for transmission and/or a target latency for the data for transmission, and the request to change mode may include an indication of said amount of data for transmission and/or said target latency.

Device 110 may transmit to apparatus 10 an indication that device 110 is to switch from the first mode to the second mode.

Device 110 may comprise means for determining that an amount of energy stored by device 110 is above a second threshold, and the transmitter 112 may transmit to the network device an indication that the apparatus is to switch from the first mode to the second mode in response to device 110 making said determination.

Figure 5 is a block diagram of an example embodiment of a device 510 (e.g. a terminal device). Device 510 is an example of a device implementing the two modes of transmission of device 110.

Device 510 comprises a transmitter 512, controller 514, and receiver 516. The transmitter 512 comprises an antenna (shared in this embodiment with the receiver 516), said antenna being coupled with an active transmitter and a load modulator.

When the transmitter 512 is operating in an active transmission mode, the active transmitter 522 may generate a signal transmitted by antenna 520. The generated signal may carry modulated data for transmission. When transmitter 512 is operating in a backscattering transmission mode, load modulator 518 may modulate the load (for example, using switches to vary the load coupled to the antenna). This may result in the backscattered signal being transmitted by the antenna when a suitable activation signal is incident on the antenna.

Figure 6 is a block diagram of a device 610 according to an example embodiment of the invention. The device 610 may be referred to as a Hybrid Energy harvesting device (H-EHD).

Device 610 comprises antenna 612, which in this example embodiment is coupled to active RF transceiver 614. Said transceiver receives transmissions and actively transmits when in an active mode (although, of course, the transceiver could be replaced with separate transmitter and receiver modules). Antenna 612 is further coupled to load modulator 616. By modulating the load, a backscattered signal may be generated to carry data when operating in a backscattering communication mode. In this example embodiment, antenna 612 is further coupled to an energy harvester 618. In some example embodiments, the energy harvester 618 may harvest energy from radio waves picked up by antenna 612.

In this embodiment, antenna 612 is coupled to energy harvester 618, RF transceiver 614, and load modulator 616. It is envisaged that in some embodiments antenna 612 may not be coupled to energy harvester 618. For example, energy harvester 618 may be a solar panel, so may not be capable of harvesting energy from radio waves incident on the antenna.

Energy harvester 618 is coupled to energy storage 620. Energy harvester 618 may harvest sufficient energy to power device 610 over a longer period, but may not be able to satisfy transient power demands, so energy harvester 618 may therefore be coupled to energy storage 620 to retain energy for use in spikes in demand. Energy harvester 618 may harvest energy in several ways. For example, energy harvester 618 may convert radio frequency signals induced in the antenna into DC current suitable for storage in a battery (which may embody energy storage 620 in some examples). In other examples, energy harvester 618 may be a solar panel or a vibration energy harvester.

Energy storage 620 may take several forms. For example, energy storage 620 may be a battery or a capacitor. The form of energy storage may be selected based upon the requirements of device 610 (such as a lifespan or reliability, a capacity, or a voltage). For example, in some use cases energy harvester 618 may be able to harvest power at a constant rate from ambient sources. In this circumstance, energy storage 620 may be selected on the basis that it has the capacity to store an amount of energy harvested between the predicted peaks of energy consumption (e.g., energy storage 620 may store enough energy to power a number of active transmissions, with the harvested energy being expected to replenish this amount between transmissions).

Device 610 comprises controller 622. Controller 622 comprises logic circuits and a memory. Controller 622 may also be responsible for managing power within device 610. Controller 622 may therefore receive energy from energy harvester 618 and/or energy storage 620, and may provide energy to active RF transceiver 614 to power active transmissions. Controller 622 may receive data from transceiver 614 regarding received signals. Controller 622 may receive data from energy harvester 618 and energy storage 620 regarding available power. Controller 622 may receive information from sensors or other data sources of device 610. Controller 622 may make determinations based on these data sources and may determine data for transmission. Controller 622 may store in its memory an indication of a transmission mode to be used and may control which of RF transceiver 614 and load modulator 616 are used to transmit data on this basis.

Figure 7 is a schematic diagram of a scenario in which a plurality of devices (H- EHDs 702 in this example scenario) are placed in a 3GPP network with gNB 704 having corresponding cell 716 and UEs 706. In this scenario, both gNB 704 and UEs 706 can be used for providing wireless power transfer (WPT) to provide energy to H-EHDs 702 for use in active transmission (type C) mode and for providing activation signals for backscattering (type A or B) mode. Both gNB 704 and UEs 706 can also be used to receive the active transmissions or backscattered signals. In some example embodiments, H-EHDs 702 can harvest energy from one or more non-3GPP sources 710 (such as sunlight, ambient artificial lighting, radio waves associated with terrestrial television broadcasts, etc.).

The network of figure 7 comprises fixed receivers 712. Said fixed receivers 712 have characteristics of a 5G UE 706, and can communicate with the gNB 704. H- EHDs 702 may be distributed in clusters 714, and fixed receivers 712 may be placed with the clusters 714. It may be advantageous to have devices with capabilities of a UE proximate the H-EHDs 702, so that the gNB 704 may task these devices with providing WPT or activation signals to H-EHDs 702.

The H-EHDs 702 are assumed to be operating in active transmission mode by default. This has the advantage that the 3GPP network does not need to provide an activation signal while said H-EHD 702 has enough energy, preferably harvested from the non-3GPP ambient source 710. Furthermore, H-EHDs 702 operating in active transmission mode can initiate data transmission when they have enough data to transmit. A backscattering mode transmission may be limited by link budget between the activator and the H-EHD 702, and may have limited range.

However, when H-EHD 702 has limited or no energy to make transmissions, it is important for the network to make use of backscattering capabilities to maintain device connectivity with the network, despite the limitations of backscattering.

Figure 8 is a signaling diagram according to an example embodiment of the invention showing actions taken at, and messages transmitted between, a network node (gNB) 840 and a device (H-END) 850. In this example embodiment, a method by which the transmission mode of a H-EHD may be controlled is provided.

At step 802, the H-EHD determines that it has data for transmission to the gNB and sufficient energy to do so using active transmission. The H-EHD may regularly generate data for transmission (for example, the H-EHD may include a sensor that regularly generates data), or the H-EHD may regularly send short messages to confirm that it has energy, and in either case the gNB may expect to receive regular communications from the H-EHD under normal conditions. Energy status updates without data from the H-EHD to the gNB may avoid the gNB unnecessarily taking actions to determine whether the H-EHD has sufficient power. The H-EHD may obtain energy for its transmissions from non-3GPP sources, such as visible light or broadcast radio waves. Additionally or alternatively, the H-EHD may obtain energy from 3GPP sources, and this may be a result of 3GPP sources such as UEs and gNBs actively directing wireless power transfer signals towards the H-EHD for harvesting. The H-EHD may operate in the active transmission mode by default.

At step 804 and in response, the H-EHD sends a request for scheduling to the gNB. Using active transmission, it is possible for the H-EHD to request resources (e.g., time/frequency resources) from the gNB, and the gNB may configure said resources. Optionally, these resources may also be used for subsequent transmissions.

At step 806, the gNB sends scheduling information to the H-EHD, and then the H- EHD transmits the data for transmission to the gNB.

At step 808, and in response to the transmission scheduled at step 806 from the H-EHD to the gNB, a timer is started or reset. This timer may correspond to or exceed a time within which the H-EHD may be expected to send data to the gNB.

Steps 802 - 806 are not essential to all example embodiments. The timer could for example be reset or initialized when the gNB first "discovers" the H-EHD, whether this is through active transmission by the H-EHD or backscattering, or at another appropriate time. Additionally, in other example embodiments the timer of step 808 may not be required. Other mechanisms may cause the gNB to send a query to the H-EHD as described below, such as a scheduled check-in with all networked H-EHDs.

At step 810, the timer exceeds a timer threshold, indicating that the H-EHD may have run out of energy and can no longer communicate using active transmission, or an attempt by the H-EHD to communicate with the gNB may have failed. Put in other words, at this step, the gNB determines that the time since the timer was last reset has exceeded a timer threshold. This timer may be configured to be longer than the expected time between transmissions from the H-EHD, or some multiple of this time. This may reduce the number of queries sent by the gNB to the H-EHD when the H-EHD has sufficient power, but its transmissions are received intermittently for other reasons (such as a lack of data).

At step 812, the gNB sends an instruction to the H-EHD to enter the backscattering transmission mode. As the H-EHD device may no longer have sufficient energy for active transmission, the H-EHD may be unable to provide information to the gNB when operating in the active transmission mode, and the H-EHD may be unable to communicate by backscattering while in active transmission mode, even if the H-EHD receives an activation signal. Also at this step, the gNB may provide energy to the H-EHD, or cause energy to be provided to the H-EHD (for example, by directing radio waves from the gNB towards the H-EHD, or by causing a UE to direct radio waves towards the H-EHD). This may be necessary if the H-EHD does not have sufficient energy to operate in backscattering transmission mode or process the instruction to enter backscattering mode. The instruction to enter the backscattering transmission mode may cause the H-EHD to enter the backscattering mode for one transmission (to respond to the query), and the H- EHD may need to receive further instructions to enter the backscattering mode again, or the instruction may cause the H-EHD to enter the backscattering mode until it receives instructions to the contrary, in which case the H-EHD will need to be instructed to enter the active transmission mode to reenter the active transmission mode. In other examples, the instruction may cause the H-EHD to enter the backscattering mode for a defined number of transmissions (e.g., two transmissions, three transmissions, etc.).

At step 814, the gNB sends a query to the H-EHD in backscattering mode. This query requests two pieces of information. First, it requests that the H-EHD confirms whether it has data to transmit. Second, it requests that the H-EHD confirms whether it has enough energy to make a transmission in the active transmission mode. This information is to confirm whether the gNB's timer expired due to the H-EHD's energy deficiency or due to another reason, including packet loss, as it is envisaged that no or a very limited HARQ system may be available for AIoT devices in some implementations. To avoid this query, H-EHD can be made to send short "dummy" data at intervals shorter than the timer threshold if it has nothing to transmit. Also at step 814, the gNB may send an activation signal to the H-EHD, to backscatter its data. The H-EHD will modulate the response to the query in this backscattered signal. In some embodiments the activation signal and query are separately sent to the H-EHD, and in other embodiments the activation signal and query are sent together.

At step 816, the H-EHD determines whether it has data to transmit. If the H-EHD does have data to transmit it can include an ACK signal for data in the response to the query, while if the H-EHD does not have data to transmit it can include a NACK signal for data in the response to the query.

At step 818, the H-EHD determines whether it has sufficient energy to make an active transmission in the active transmission mode. In particular, the H-EHD may determine whether it has sufficient energy to transmit some or all of the data that it is to transmit in the active transmission mode. In some example embodiments the amount of energy needed (or estimated to be needed) to transmit some of the data in the active transmission mode may be associated with a threshold that the H-EHD may compare to an amount of energy stored by the H-EHD. In other example embodiments, a threshold may be defined based on the amount of energy needed (or estimated to be needed) to transmit all of the data in the active transmission mode. If the H-EHD has sufficient energy it includes in the response the ACK signal for energy. If the H-EHD has insufficient energy it includes the NACK signal for energy in the response.

At step 820, the H-EHD modulates a response including the aforementioned determination results onto the backscattered signal, and this response is received by the gNB. The response to the query may further include information on the size of the data to be transmitted, and the latency requirements for the transmission.

At step 822, the gNB determines whether the response includes a data NACK signal. If the response includes a data NACK signal, the method may return to step 808 to reset and/or restart the timer, as the lack of data to be sent by the H-EHD can be presumed to be the cause of not receiving a transmission before the timer exceeds a threshold. If the response includes a data ACK signal, the method proceeds to step 824.

At step 824, the gNB determines whether the response includes an ACK signal for energy. If the gNB determines that the response includes an ACK signal for data and energy, then the method may proceed to step 830, as the H-EHD has sufficient energy to transmit its data.

If at step 824 the gNB determines that the response includes a NACK signal for energy, the gNB must determine a suitable mode for the H-EHD to operate in. The gNB may take the position of the H-EHD device into account (for example, whether the H-EHD is at the edge of the coverage of the gNB), and the gNB may take the presence and position of other 3GPP devices into account (for example, whether a UE or other device that may provide an activation signal or energy for harvesting to the H-EHD is present).

The gNB therefore decides whether the H-EHD should transmit the data using backscattering communication, and/or whether the H-EHD should be provided with energy to enable active transmission. If the gNB decides that energy should be provided to the H-EHD, it must then decide on the source of that energy, for instance, the gNB may decide on which device should act as a source of RF signals for activation signal or wireless power transfer.

While backscattering communication may be suitable for the response to the query, it may be unsuitable for transmitting large volumes of data, as comparably less data can typically be included into a backscattered communication than an active transmission of similar length, and if the H-EHD is distant from the gNB (or another source of an activation signal) the activation signal may need to be powerful for the backscattered signal to have sufficient strength. If the activation signal required is too powerful, this may generate an unacceptable level of interference. Wireless power transfer (WPT) to the H-EHD may be suitable if powerful sources of wireless power are present near the H-EHD, or if the latency requirements are low (i.e., the data is not urgent), so a longer energy harvesting period is appropriate. However, for small amounts of data that have strict latency requirements, backscattering may be preferable.

The gNB therefore decides at this stage on the mode of transmission that the H- EHD should use, and, if applicable, the source of energy that should provide energy to the H-EHD. Said deciding on an energy source may be deciding on a source of a backscattering activation signal, or deciding on a source of a wireless power transfer signal.

The gNB may need to decide which of several 3GPP devices should be used as the energy source, such as a power beacon, UEs, or the gNB itself. Whether a source may be used may depend on the gNB link budget and the link budget of the potential source (such as a UE).

The decisions regarding which mode to use and which energy source to use may not be completely independent. For example, if no suitable alternative energy sources are available to provide WPT or activation signals, and the H-EHD is at the cell edge, then the required activation signal to generate a suitable backscatter may be so powerful that it would generate an unacceptable amount of interference. In this case the gNB may decide to send WPT signals of relatively lower power for a longer period of time, so that the H-EHD may transmit in active mode when the energy stored is sufficient. If the H-EHD is close to the gNB, backscattering mode may be preferable because longer range is not required and backscattering mode may consume less energy.

This decision could be made based on simple rules (e.g., H-EHDs within a certain distance of the gNB or their nearest UE should use backscattering mode, and otherwise WPT should be used), or the gNB could use more complicated rules (e.g., the gNB could compare the time required to provide sufficient energy using WPT from different possible sources to latency requirements, and/or compare the required power of the backscattering activation signal from different possible sources to allowable limits as part of its determinations), and make the decision based upon these factors.

Once the gNB has determined the mode of transmission to be used, at 826 the gNB sends a mode indicator signal to the H-EHD. In some example embodiments the gNB is aware of the current mode of the H-EHD and only sends a mode indicator signal if the mode is to change. In other embodiments, the gNB sends a mode indicator signal regardless. While the gNB decides on which mode should be used and which energy source should be used, it may not be necessary to communicate the energy source to the H-EHD, as information on the source of the activation signal or the source of the WPT may not be needed by the H-EHD.

At step 828, and in response, the H-EHD sets its mode to the mode indicated by the mode indicator signal. Depending on what mode is chosen by the gNB and whether the instruction at step 812 caused the H-EHD to enter backscattering mode for one transmission only, or indefinitely, this may mean that the mode does not change.

At step 830, if the mode selected at step 824 is the active transmission mode, or if the H-EHD was determined to have sufficient energy for active transmission, the gNB sends scheduling information to the H-EHD for active transmission. The gNB may also provide the H-EHD with an RF signal (such as a WPT signal) at this step, or cause the H-EHD to be provided with RF signal (e.g. by providing instructions to a UE), if the H-EHD was determined to have insufficient energy.

If the mode selected at step 824 was the backscattering mode, the gNB may instead send an activation signal to the H-EHD, or cause an activation signal to be send (for example, by a UE), to be backscattered by the H-EHD.

The mode indicator signal at step 826 may instruct the H-EHD to enter the backscattering mode for only one or a fixed number of transmissions. If the harvested energy is expected to improve fast before the next transmission, this may be suitable. Otherwise, switching back to the active transmission mode after only one backscattering transmission may cause the above procedure to be repeated.

In some embodiments, this is avoided by having the mode indicator signal at step 826 instruct the H-EHD to enter the backscattering mode until some condition is met.

In some embodiments, the gNB may send activation signals to the H-EHD regularly, so that data from the H-EHD may be modulated into the backscatter regularly.

While the above example method has been described by reference to a H-EHD in a network with a gNB, the aspects of the above method can be extended to other communication systems including terminal devices (such as the H-EHD) and network devices (such as the gNB). For example, aspects of the above method could be applied to a system in which a terminal device is in receipt of unreliable energy from any source. For example, an instruction from the network device to switch modes could be useful for maintaining a minimum level of communication between the terminal device and network device if an emergency or other circumstance causes the terminal device to lose power. In such a situation, the terminal device may normally operate using grid power (from a national or regional power grid or a combustion powered generator for example) and may rely on unpowered backscattering communication if grid power becomes unavailable.

Figure 9 is a signaling diagram according to an example embodiment of the invention showing actions taken at, and messages transmitted between, a network node (gNB) 940 and a device (H-END) 950. In this example embodiment, a method by which the H-EHD may return to the active transmission mode from the backscattering mode is provided.

In some example embodiments, this method follows the method of figure 8.

In some example embodiments, the H-EHD can by default switch back to the active transmission mode after making one backscattering transmission, and the network may be required to repeat the above procedure if it still does not receive a transmission after expiry of the timer again.

This may not be efficient if the time T after which the gNB sends a further query to the H-EHD is short, and the harvested energy is not expected to improve sufficiently in this time. Rather than returning to the active transmission mode by default, in some example embodiments the H-EHD may provide an explicit mode change indication when it has sufficient energy to operate in the active transmission mode by sending an indication signal with backscattered data that it has enough energy to operate in the active transmission mode, and the gNB can stop sending the activation signal on receiving this message. This signaling assumes that gNB is acting as an activator but similar signaling may be used if another 3GPP device is used as activator. In such cases, the H-EHD message may be received by a reader device and forwarded to the activator device through the 3GPP network, which may then stop sending activation signals.

At step 902, the H-EHD is in backscattering mode. To retrieve data from the H- EHD, the gNB may send an activation signal to the H-EHD (or cause an activation signal to be sent).

At step 904, the H-EHD determines that it should enter active transmission mode. This may be based on one or more of, or a combination of: the H-EHD determining that its energy storage is above a threshold, the H-EHD determining that the rate at which it is harvesting energy is above a threshold, or the H-EHD determining that it has data for transmission above a certain size.

At step 906, the gNB sends the activation signal as usual.

At step 908, the H-EHD sends the gNB the data for transmission in the backscattered signal, and also the H-EHD also includes in the backscattered signal a request to switch back to the active transmission mode. In some example embodiments the H-EHD may send the request without sending the data.

Upon receipt of the request at step 908, the gNB may determine that it is no longer necessary to send activation signals to the H-EHD, as the H-EHD intends to transmit in the active mode. The gNB may therefore stop sending activation signals. If the gNB has tasked another network device with sending activation signals to the H-EHD, the gNB may instruct that device to stop sending activation signals.

At step 910, the gNB sends the H-EHD an instruction or an acknowledgement to switch mode to the active transmission mode. In some embodiments, the H-EHD may determine that it has not received an activation signal in a particular amount of time and determine that it is to transmit in the active transmission mode. In some embodiments the gNB does not send an instruction or acknowledgement at step 910 and relies upon the H-EHD determining that it is to change modes from the lack of activation signals, and/or from storing sufficient energy. In some embodiments, the H-EHD may switch to the active mode either when it receives an instruction or acknowledgement to do so, when it does not receive activation signals, or when an amount of stored energy is above a threshold.

At step 912, in response, the H-EHD sets its mode to the active transmission mode. From this point, the H-EHD is operating in the active transmission mode, and steps 802 - 808 of the method of figure 8 may take place, and may repeat until step 810 or another process takes place.

Figure 10 is a signaling diagram according to an example embodiment of the invention. In this example embodiment, a method by which a H-EHD 1050 may request to change its mode of transmission is provided. In a previously discussed embodiment, it was gNB 840 (or other network device) that determined that H- EHD 850 should be queried (for example, because the H-EHD may have run out of energy). In this embodiment H-EHD 1050 sends a request to gNB 1040 to change mode.

Steps 1002 - 1008 correspond to steps 802 - 808 of the method of figure 8. These steps may represent normal operation in the active transmission mode in the presence of sufficient harvested energy in some example embodiments. It is not essential to all example embodiments that step 1010 is preceded by these steps.

At step 1010, the H-EHD determines that it has data to transmit. The H-EHD may determine a size of the data for transmission, and a latency target.

At step 1012, the H-EHD determines whether sufficient energy is available for active transmission of the data.

If at step 1012 the H-EHD determines that there is insufficient energy available for active transmission, at step 1014 the H-EHD sends a mode change request to the gNB. This mode change request may in some example embodiments merely indicate that the H-EHD intends to use a backscattering mode of transmission. In other embodiments the mode change request may include information indicating such as for example, the amount of data for transmission, and the latency target for this transmission, so that the gNB may make a better informed decision on the transmission mode that the H-EHD is to use.

This mode change request is transmitted in the active transmission mode, as the gNB has not been prompted to send activation signals to the H-EHD to enable backscattering communication. There may therefore be sufficient energy available to the H-EHD for the H-EHD to send a short mode change request, but insufficient energy to send the data for transmission. In other embodiments the H-EHD may send the mode change request if the stored energy is below a threshold (for example, the H-EHD may send the mode change request if its energy drops below a safety margin, even if sufficient energy is available to communicate the data).

If the mode change request is not received by the gNB, the H-EHD may not enter the backscattering mode and may have insufficient power to send a further request. In some embodiments this situation may be resolved by steps 810 - 826 of the method of figure 3 taking place, but having this process in place as a backup is not essential to the working of this method of H-EHD initiated mode switching.

Upon receiving the mode change request, the gNB determines at step 1016 which mode should be used by the H-EHD. The factors considered by the gNB may correspond to those considered at step 824 of the method of figure 3.

At step 1018, the gNB sends a signal to the H-EHD, instructing it to use the mode determined at step 1016. This signal may instruct the H-EHD to use this mode for only one communication, a determined number of communications, or until further notice.

At step 1020, the H-EHD sets its mode to the indicated mode accordingly.

In some example embodiments, the method of figure 9 may be carried out when the energy in the H-EHD is sufficient.

Figure 11 is a flow diagram of a method 1100 according to an example embodiment of the invention. Method 1100 may be carried out by apparatus 10.

At step 1110 apparatus 10 provides a query to an energy harvesting device.

Said energy harvesting device may be device 110. Said energy harvesting device comprises means for transmitting data in active and backscattering modes, wherein, in the backscattering mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the active mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated. Said means for transmitting may be transmitter 112 and said query may be provided using transmitter 12.

At step 1112 apparatus 10 obtains a response to said query from said energy harvesting device. Said response may be obtained using receiver 16 and said energy harvesting device may provide the response using transmitter 112.

At step 1114 apparatus 10 selects one of the active mode and the backscattering mode based at least in part on said response. In some example embodiments said response may include information indicating whether an amount of energy stored by the energy harvesting device is above or below a first threshold, and the mode selected may be based at least in part on whether the amount of energy stored is above or below said first threshold. In some example embodiments, apparatus 10 may select the active mode based upon the amount of energy stored being above said first threshold. Additionally, or alternatively, apparatus 10 may select the active mode or the backscattering mode based upon the amount of energy stored being below said first threshold.

At step 1116 apparatus 10 provides said energy harvesting device an instruction to operate in the selected mode for one or more transmissions. For example, said instruction may be provided by transmitting an instruction to said energy harvesting device using transmitter 12.

In some example embodiments, apparatus 10 provides to device 110 before providing the query a second instruction, said second instruction being an instruction to operate in the backscattering mode.

The query may comprise an activation signal for backscattering by device 110, and device 110 may be configured to modulate the response to said query on the backscattered signal.

Apparatus 10 may provide an activation signal or a wireless power transfer signal to device 110, or apparatus 10 may instruct another network entity to provide an activation signal or a wireless power transfer signal to device 110.

The response may comprise data indicating whether an amount of energy stored by device 110 is above a first threshold, the active mode may be selected if the response indicates that said amount of energy is above said first threshold.

The response may comprise data indicating whether an amount of energy stored by device 110 is above a/the first threshold, and the active mode or the backscattering mode may be selected if the response indicates that said amount of energy stored is below said first threshold.

Apparatus 10 may determine an amount of time that has elapsed since the receipt of a previous transmission by device 110, and may provide said query in response to the determined amount of elapsed time exceeding a timer threshold.

The response may comprise data indicating whether device 110 has data to transmit, and the apparatus 10 may reset the determined time that has elapsed since the receipt of a previous transmission, if said response indicates that device 110 does not have data to transmit.

The active or the backscatter mode may be selected based on at least one of an amount of data buffered at device 110, a target latency, a distance between apparatus 10 and device 110, or a determination of whether to provide an activation signal to device 110.

Apparatus 10 may receive from device 110 an indication that device 110 is to switch from the backscattering mode to the active mode.

Figure 12 is a flow diagram of a method 1200 according to an example embodiment of the invention. Method 1200 may be carried out by an apparatus such as device 110. The device 110 may be an energy harvesting device.

At step 1210 device 110 receives a query from a network device. Said network may be device 10.

At step 1212 device 110 transmits a response to said query to apparatus 10 using transmitter 112.

At step 1214 device 110 receives an instruction from apparatus 10 to operate in one of the backscattering and active modes for one or more transmissions.

At step 1216 device 110 sets the mode in which transmitter 112 operates to the instructed mode.

Device 110 may receive a second instruction before receiving the query, said second instruction being an instruction to switch the mode in which transmitter 112 operates to the backscattering mode, and wherein transmitter 112 is configured to operate in the backscattering mode in response to the receipt of said second instruction.

Transmitting the response to the query may comprise modulating the response on a backscattered transmission.

Device 110 may determine whether an amount of energy stored by device 110 is above a threshold, and the response may comprise information indicating whether said amount of energy stored is above said threshold.

Device 110 may determine whether device 110 has data for transmission to apparatus 10, and the response may comprise information indicating whether device 110 has data for transmission.

Device 110 may transmit to the network device an indication that device 110 is to switch from the backscattering mode to the active mode.

Device 110 may determine whether an amount of energy stored by device 110 is above a second threshold. Device 110 may transmit to the network device an indication that the apparatus is to switch from the backscattering mode to the active in response to making said determination.

Figure 13 is a flow diagram of a method 1300 according to an example embodiment of the invention. Method 1300 may be carried out by apparatus 10.

At step 1310 apparatus 10 receives a request from an energy harvesting device. Said energy harvesting device may be device 110.

At step 1312 apparatus 10 selects a mode of the active and backscattering modes based at least in part on said request.

At step 1314 apparatus 10 provides to device 110 an instruction to operate in the selected mode for one or more transmissions. The request may be a request to operate in the backscattering mode.

The request may include at least one of an amount of data to be transmitted by device 110 or a target latency.

Apparatus 10 may select the backscattering mode or the active mode based on at least one of an amount of data buffered at device 110, a target latency, a distance between the apparatus 10 and device 110, or a determination of whether to provide an activation signal to device 110.

Apparatus 10 may determine an amount of time that has elapsed since the receipt of a previous transmission by device 110, and may provide a query to said device if neither of a transmission or said request is received before the determined amount of elapsed time exceeds a timer threshold.

Figure 14 is a flow diagram of a method 1400 according to an example embodiment of the invention. Method 1400 may be carried out by an apparatus such as device 110. The device 110 may be an energy harvesting device.

At step 1410 device 110 transmits a request for reception by a network device. Said network device may be apparatus 10.

In some embodiments device 110 may generate said request in response to device 110 determining that an amount of energy stored by device 110 is below a threshold and/or determining that device 110 has data for transmission to apparatus 10.

At step 1412 device 110 receives an instruction from apparatus 10 to operate in a mode of the backscattering and active modes for one or more transmissions.

At step 1414 device 110 sets the mode in which the transmitter 12 operates to the instructed mode.

Device 110 may determine that an amount of energy stored by device 110 is below a first threshold and determine that device 110 has data for transmission to apparatus 10, and in response to making said determinations, transmit the request to apparatus 10, and the request may be a request to change the mode in which the transmitter operates to a backscattering mode.

Device 110 may transmit to apparatus 10 an indication that device 110 is to switch from the backscattering mode to the active mode.

Device 110 may determine that an amount of energy stored by the device is above a second threshold, and the indication that device 110 is to switch from the backscattering mode to the active mode may be transmitted in response to making said determination.

For completeness, FIG. 15 is a schematic diagram of components of one or more of the example embodiments described previously, which hereafter are referred to generically as a processing system 1500. The processing system 1500 may, for example, be comprised by the apparatus referred to in the claims below.

The processing system 1500 may have a processor 1502, a memory 1504 closely coupled to the processor and comprised of a RAM 1514 and a ROM 1512, and, optionally, a user input 1510 and a display 1518. The processing system 1500 may comprise one or more network/apparatus interfaces 1508 for connection to a network/apparatus, e.g. a modem which may be wired or wireless. The network/apparatus interface 1508 may also operate as a connection to other apparatus such as device/apparatus which is not network side apparatus. Thus, direct connection between devices/apparatus without network participation is possible.

The processor 1502 is connected to each of the other components in order to control operation thereof.

The memory 1504 may comprise a non-volatile memory, such as a hard disk drive (HDD) or a solid state drive (SSD). The ROM 1512 of the memory 1504 stores, amongst other things, an operating system 1515 and may store software applications 1516. The RAM 1514 of the memory 1504 is used by the processor 1502 for the temporary storage of data. The operating system 1515 may contain code which, when executed by the processor implements aspects of the methods 300, 400, 1100, 1200, 1300, and 1400 described above, along with aspects of the signalling steps of figures 8, 9, and 10. Note that in the case of small device/apparatus the memory can be most suitable for small size usage i.e. not always a hard disk drive (HDD) or a solid state drive (SSD) is used.

The processor 1502 may take any suitable form. For instance, it may be a microcontroller, a plurality of microcontrollers, a processor, or a plurality of processors.

The processing system 1500 may be a standalone computer, a server, a console, or a network thereof. The processing system 1500 and needed structural parts may be all inside device/apparatus such as loT device/apparatus i.e. embedded to very small size.

In some example embodiments, the processing system 1500 may also be associated with external software applications. These may be applications stored on a remote server device/apparatus and may run partly or exclusively on the remote server device/apparatus. These applications may be termed cloud-hosted applications. The processing system 1500 may be in communication with the remote server device/apparatus in order to utilize the software application stored there. FIG. 16 shows a tangible media, in the form of a removable memory unit 1610, storing computer-readable code which when run by a computer may perform methods according to example embodiments described above. The removable memory unit 1610 may be a memory stick, e.g. a USB memory stick, having internal memory 1630 storing the computer-readable code. The internal memory 1630 may be accessed by a computer system via a connector 1620. Of course, other forms of tangible storage media may be used, as will be readily apparent to those of ordinary skilled in the art. Tangible media can be any device/apparatus capable of storing data/information which data/information can be exchanged between devices/apparatus/network.

Embodiments of the present invention may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic and/or hardware may reside on memory, or any computer media. In an example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer-readable media. In the context of this document, a "memory" or "computer-readable medium" may be any non-transitory media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.

Reference to, where relevant, "computer-readable medium", "computer program product", "tangibly embodied computer program" etc., or a "processor" or "processing circuitry" etc. should be understood to encompass not only computers having differing architectures such as single/multi-processor architectures and sequencers/parallel architectures, but also specialised circuits such as field programmable gate arrays FPGA, application specify circuits ASIC, signal processing devices/apparatus and other devices/apparatus. References to computer program, instructions, code etc. should be understood to express software for a programmable processor firmware such as the programmable content of a hardware device/apparatus as instructions for a processor or configured or configuration settings for a fixed function device/apparatus, gate array, programmable logic device/apparatus, etc. If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined. Similarly, it will also be appreciated that the flow and signalling diagrams of Figures 3, 4, 8, 9, 10, 11, 12, 13, and 14 are examples only and that various operations depicted therein may be omitted, reordered and/or combined.

It will be appreciated that the above-described example embodiments are purely illustrative and are not limiting on the scope of the invention. Other variations and modifications will be apparent to persons skilled in the art upon reading the present specification.

Moreover, the disclosure of the present application should be understood to include any novel features or any novel combination of features either explicitly or implicitly disclosed herein or any generalization thereof and during the prosecution of the present application or of any application derived therefrom, new claims may be formulated to cover any such features and/or combination of such features.

Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described example embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

It is also noted herein that while the above describes various examples, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims.

Claims

1. An apparatus, comprising: means for obtaining information, said information being associated with one or more transmissions from a terminal device, said terminal device comprising: means for transmitting data in first and second modes, wherein, in the first mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; means for selecting, based at least in part on said information, a mode of the first and second modes; and means for providing to said terminal device an instruction to operate in the selected mode for one or more transmissions.

2. The apparatus of claim 1, further comprising means for providing a query to the terminal device, wherein the information comprises a response to said query, and wherein the means for selecting a mode of the first and second modes selects the mode based at least in part on said response.

3. The apparatus of claim 2, further comprising means for providing to the terminal device before providing the query a second instruction, said second instruction being an instruction to operate in the first mode.

4. The apparatus of claim 3, wherein the query comprises an activation signal for backscattering by the terminal device, wherein said terminal device is configured to modulate the response to said query on the backscattered signal.

5. The apparatus of any of claims 2 - 4, wherein said response comprises data indicating whether an amount of energy stored by the terminal device is above a first threshold, and wherein said means for selecting selects the second mode if the data indicates that an amount of energy stored is above said first threshold.

6. The apparatus of any of claims 2 - 5, wherein said response comprises data indicating whether an amount of energy stored by the terminal device is above a/the first threshold, and wherein said means for selecting selects the first mode or the second mode if the data indicates that an amount of energy stored is below said first threshold.

7. The apparatus of any of claims 2 - 6, further comprising means for determining an amount of time that has elapsed since the receipt of a previous transmission by said terminal device, and wherein the means for providing said query provides said query in response to the determined amount of elapsed time exceeding a timer threshold.

8. The apparatus of any of claims 2 - 7, wherein the response comprises data indicating whether the terminal device has data to transmit, and wherein the apparatus further comprises: means for resetting a determined time that has elapsed since the receipt of a previous transmission, if said response indicates that the terminal device does not have data to transmit.

9. The apparatus of claim 1, wherein the information comprises a request, and wherein the means for selecting a mode of the first and second modes selects the mode based at least in part on said request.

10. The apparatus of claim 9, wherein the request is a request to operate in the first mode.

11. The apparatus of claim 10, wherein the request further includes at least one of an amount of data to be transmitted by the terminal device, or a target latency.

12. The apparatus of any one of the preceding claims, wherein said means for selecting selects the first or the second mode based on at least one of an amount of data buffered at the terminal device, a target latency, a distance between the apparatus and the terminal device, or a determination of whether to provide an activation signal to the terminal device.

13. The apparatus of any one of the preceding claims, further comprising means for receiving from the terminal device an indication that the terminal device is to switch from the first mode to the second mode.

14. An apparatus, comprising: means for transmitting data in first and second modes, wherein, in the first mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; means for transmitting information to a network device using said means for transmitting data; means for receiving an instruction from said network device to operate in one of the first and second modes for one or more transmissions; and means for setting the mode, in which the data transmitting means operates, to the instructed mode.

15. The apparatus of claim 14, further comprising means for receiving a query from the network device, wherein the means for transmitting information is configured to transmit a response to said query.

16. The apparatus of claim 15, further comprising means for receiving a second instruction before receiving the query, said second instruction being an instruction to switch the mode in which the means for transmitting data operates to the first mode, and wherein the means for transmitting data are configured to operate in the first mode in response to the receipt of said second instruction.

17. The apparatus of claim 15 or 16, wherein transmitting the response to said query comprises modulating the response on a backscattered transmission.

18. The apparatus of any of claims 14 - 17, further comprising means for determining whether an amount of energy stored by the apparatus is above a threshold, and wherein the response comprises information indicating whether said amount of energy stored is above said threshold.

19. The apparatus of any of claims 14 - 18, further comprising means for determining whether the apparatus has data for transmission to the network device, and wherein the response comprises information indicating whether the apparatus has data for transmission.

20. The apparatus of claim 14, further comprising means for determining that an amount of energy stored by said apparatus is below a first threshold and that the apparatus has data for transmission to said network device, and wherein, in response to making said determination, the means for transmitting information is configured to transmit a request to change the mode in which the means for transmitting data operates to the first mode.

21. The apparatus of claim 20, further comprising means for determining an amount of data for transmission and/or a target latency for the data for transmission, and wherein the request to change mode includes an indication of said amount of data for transmission and/or the target latency.

22. The apparatus of any of claims 14 - 21, further comprising means for transmitting to the network device an indication that the apparatus is to switch from the first mode to the second mode.

23. The apparatus of claim 22, further comprising means for determining that an amount of energy stored by said apparatus is above a second threshold, wherein the means for transmitting to the network device an indication that the apparatus is to switch from the first mode to the second mode are configured to transmit said indication in response to making said determination.

24. A method, comprising: obtaining information, said information being associated with one or more transmissions from a terminal device, said terminal device comprising: means for transmitting data in first and second modes, wherein, in the first mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; selecting, based at least in part on said information, a mode of the first and second modes; and providing to said terminal device an instruction to operate in the selected mode for one or more transmissions.

25. A method, comprising: transmitting information to a network device using a means for transmitting data, wherein said means for transmitting data is configured to transmit data in first and second modes, wherein, in the first mode, transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; receiving an instruction from said network device to operate in one of the first and second modes for one or more transmissions; and setting the mode, in which the data transmitting means operates, to the instructed mode.

26. An apparatus, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: obtain information, said information being associated with one or more transmissions from a terminal device, said terminal device is configured to transmit data in first and second modes, wherein, in the first mode transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; select, based at least in part on said information, a mode of the first and second modes; and provide to said terminal device an instruction to operate in the selected mode for one or more transmissions.

27. An apparatus, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: transmit information to a network device, wherein said apparatus is configured to transmit data in first and second modes, wherein, in the first mode, transmitting data comprises modulating said data on a backscattered signal, and wherein, in the second mode transmitting data comprises actively generating and transmitting a signal on which said data is modulated; receive an instruction from said network device to operate in one of the first and second modes for one or more transmissions; and set the mode, in which the data is transmitted, to the instructed mode.

28. A computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least the method of claim 24 or 25.