Apparatus, method, and computer program

Abstract

An ambient Internet of Things (A-IoT) device receives, from a reader, a reader to device signal (R2D) comprising an indication to determine a measured delay corresponding to a measured clock count bet

Description

Field of the disclosure The present disclosure relates to an Internet of things device, a method, and a computer program for managing an Internet of things device (e.g., ambient Internet of things device) in a communication system. Background A communication system can be seen as a facility that enables communication sessions between two or more entities such as communication devices, base stations (BSs) and / or other nodes by providing carriers between the various entities involved in the communications path. The communication system may be a wireless communication system. Examples of wireless systems comprise public land mobile networks (PLMN) operating based on radio standards such as those provided by 3GPP, satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). The wireless systems can typically be divided into cells, and are therefore often referred to as cellular systems. The communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and / or parameters which shall be used for the connection are also typically defined. Examples of standard are 4G, 5G or 6G standards. Summary According to an aspect there is provided an Internet of things device comprising: means for receiving, from a reader, a reader to device signal comprising an indication to transmit, to the reader, a device to reader signal after a pre-determined delay corresponding to a pre-determined clock count; and means for transmitting, to the reader, a device to reader signal after the pre-determined delay. The pre-determined delay may be a time duration (e.g., time difference) between transmitting, to the reader, the device to reader signal and receiving, from the reader, a reader to device signal. The pre-determined delay may be different from an internal delay for processing at least one of a reader to device signal or a device to reader signal. The pre-determined delay may be taken into consideration by the reader for determining at least one of a round trip time between the reader and the device or a distance between the reader and the device. The pre-determined delay may be greater than the internal delay for processing at least one of a reader to device signal or a device to reader signal. The internal delay for processing at least one of a reader to device signal or a device to reader signal may comprise a maximum internal delay for processing at least one of a reader to device signal or a device to reader signal. The internal delay for processing at least one of a reader to device signal or a device to reader signal may be set in the standards. The internal delay for processing at least one of a reader to device signal or a device to reader signal may depend on a class of the device. That is, devices with different classes may have different internal delays for processing at least one of a reader to device signal or a device to reader signal. Processing a reader to device signal may comprise decoding a reader to device signal Processing the device to reader signal may comprise encoding (e.g., and preparing) a device to reader signal for transmission. The pre-determined delay may be indicated in the reader to device signal. The pre-determined delay may be configured in the device and the reader. The pre-determined delay may be set in the standards. The pre-determined delay may be one of a plurality of pre-determined delays set in the standards. The one of the plurality of pre-determined delays set in the standards may be indicated in the reader to device signal. The means for receiving, from a reader, a reader to device signal comprising an indication to transmit, to the reader, an device to reader signal after a pre-determined delay may comprise: means for triggering a clock count upon receiving , from the reader, the reader to device signal; and means for determining that the clock count has reached the pre-determined clock count corresponding to the pre-determined delay. The reader to device signal may comprise at least one of: a synchronisation signal; or a payload. The synchronisation signal may comprise at least one of: a delimiter; ora clock signal. The clock signal may comprise a square wave signal. The means for waiting for the pre-determined delay may comprise: means for synchronising a clock signal of a clock oscillator with the synchronisation signal. The device may comprise: means for transmitting, to the reader, a prior device to reader signal comprising a report of device capabilities. The report of device capabilities may comprise at least one of: whether the Internet of things device comprises a clock oscillator; an internal delay for processing at least one a reader to device signal or a device to reader signal; or a duration during which the Internet of things device maintains synchronisation between a clock signal of an oscillator and a clock signal of a synchronisation signal after receiving the clock signal of the synchronisation signal. The device may comprise: means for determining that the pre-determined delay is lower than an internal delay for processing the reader to device signal and an internal delay for processing the device to reader signal; and means for transmitting, to the reader, a device to reader signal comprising an indication to extend the predetermined delay. The device may comprise: means for receiving, from the reader, a report of an extension of the pre-determined delay; and means for extending the pre-determined delay based on the extension of the pre-determined delay. The device may comprise: means for determining an extension of the pre-determined delay; means for transmitting, to the reader, a report of the extension of the predetermined delay; and means for extending the pre-determined delay based on the extension of the pre-determined delay. An extension of the pre-determined delay may comprise an additional clock count. The reader to device signal may comprise an indication that the reader to device signal is for determining a round trip time between the reader and the device; and / or the device to reader signal may comprise an indication that the device to reader signal is for determining at least one of a round trip time between the reader and the device or a distance between the reader and the device. The indication that the reader to device signal may be for determining at least one of a round trip time between the reader and the device or a distance between the reader and the device may comprise a pre-determined sequence or reference signal. The Internet of things device may comprise an ambient Internet of Things device. According to an aspect there is provided a method comprising: receiving, from a reader, a reader to device signal comprising an indication to transmit, to the reader, a device to reader signal after a pre-determined delay corresponding to a predetermined clock count; and transmitting, to the reader, a device to reader signal after the pre-determined delay. The method may be performed by an Internet of things device. The pre-determined delay may be a time duration (e.g., time difference) between transmitting, to the reader, the device to reader signal and receiving, from the reader, a reader to device signal. The pre-determined delay may be different from an internal delay for processing at least one of a reader to device signal or a device to reader signal. The pre-determined delay may be taken into consideration by the reader for determining at least one of a round trip time between the reader and the device or a distance between the reader and the device. The pre-determined delay may be greater than the internal delay for processing at least one of a reader to device signal or a device to reader signal. The internal delay for processing at least one of a reader to device signal or a device to reader signal may comprise a maximum internal delay for processing at least one of a reader to device signal or a device to reader signal. The internal delay for processing at least one of a reader to device signal or a device to reader signal may be set in the standards. The internal delay for processing at least one of a reader to device signal or a device to reader signal may depend on a class of the device. That is, devices with different classes may have different internal delays for processing at least one of a reader to device signal or a device to reader signal. Processing a reader to device signal may comprise decoding a reader to device signal Processing the device to reader signal may comprise encoding (e.g., and preparing) a device to reader signal for transmission. The pre-determined delay may be indicated in the reader to device signal. The pre-determined delay may be configured in the device and the reader. The pre-determined delay may be set in the standards. The pre-determined delay may be one of a plurality of pre-determined delays set in the standards. The one of the plurality of pre-determined delays set in the standards may be indicated in the reader to device signal. The receiving, from a reader, a reader to device signal comprising an indication to transmit, to the reader, an device to reader signal after a pre-determined delay may comprise: triggering a clock count upon receiving , from the reader, the reader to device signal; and determining that the clock count has reached the pre-determined clock count corresponding to the pre-determined delay. The reader to device signal may comprise at least one of: a synchronisation signal; or a payload. The synchronisation signal may comprise at least one of: a delimiter; ora clock signal. The clock signal may comprise a square wave signal. The waiting for the pre-determined delay may comprise: synchronising a clock signal of a clock oscillator with the synchronisation signal. The method may comprise: transmitting, to the reader, a prior device to reader signal comprising a report of device capabilities. The report of device capabilities may comprise at least one of: whether the Internet of things device comprises a clock oscillator; an internal delay for processing at least one a reader to device signal or a device to reader signal; or a duration during which the Internet of things device maintains synchronisation between a clock signal of an oscillator and a clock signal of a synchronisation signal after receiving the clock signal of the synchronisation signal. The method may comprise: determining that the pre-determined delay is lower than an internal delay for processing the reader to device signal and an internal delay for processing the device to reader signal; and transmitting, to the reader, a device to reader signal comprising an indication to extend the pre-determined delay. The method may comprise: receiving, from the reader, a report of an extension of the pre-determined delay; and extending the pre-determined delay based on the extension of the pre-determined delay. The method may comprise: determining an extension of the pre-determined delay; transmitting, to the reader, a report of the extension of the pre-determined delay; and extending the pre-determined delay based on the extension of the pre-determined delay. An extension of the pre-determined delay may comprise an additional clock count. The reader to device signal may comprise an indication that the reader to device signal is for determining a round trip time between the reader and the device; and / or the device to reader signal may comprise an indication that the device to reader signal is for determining at least one of a round trip time between the reader and the device or a distance between the reader and the device. The indication that the reader to device signal may be for determining at least one of a round trip time between the reader and the device or a distance between the reader and the device may comprise a pre-determined sequence or reference signal. The Internet of things device may comprise an ambient Internet of Things device. According to an aspect there is provided an Internet of things device comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the Internet of things device at least to perform: receiving, from a reader, a reader to device signal comprising an indication to transmit, to the reader, a device to reader signal after a pre-determined delay corresponding to a pre-determined clock count; and transmitting, to the reader, a device to reader signal after the pre-determined delay. According to an aspect there is provided an Internet of things device comprising circuitry configured to perform: receiving, from a reader, a reader to device signal comprising an indication to transmit, to the reader, a device to reader signal after a pre-determined delay corresponding to a pre-determined clock count; and transmitting, to the reader, a device to reader signal after the pre-determined delay. According to an aspect there is provided a computer program comprising computer executable code which when run on at least one processor is configured to perform: receiving, from a reader, a reader to device signal comprising an indication to transmit, to the reader, a device to reader signal after a pre-determined delay corresponding to a pre-determined clock count; and transmitting, to the reader, a device to reader signal after the pre-determined delay. According to an aspect there is provided a reader comprising: means for transmitting, to an Internet of things device, a reader to device signal comprising an indication to transmit, to the reader, a device to reader signal after a pre-determined delay corresponding to a pre-determined clock count; and means for receiving, from the Internet of things device, a device to reader signal after the pre-determined delay. The reader may comprise: means for determining a transmission time of a reader to device signal; means for determining a reception time of the Internet of things device to reader signal; and means for determining a round trip time between the reader and the Internet of things device based on the transmission time, the reception time, and the pre-determined delay. The reader may comprise: means for determining a distance between the reader and the Internet of things device based on the round-trip time between the reader and the Internet of things device. The reader may comprise: means for determine that the distance meets a distance criterion; and means for serving the Internet of things device. The distance criterion may comprise the distance is smaller than a distance threshold. The reader may comprise: means for receiving, from a base station, configuration information comprising a report of the distance criterion. The configuration information may be received via radio resource control or system information block. The reader may comprise: means for transmitting, to a base station, a report of the round-trip time between the reader and the Internet of things device; means for transmitting, to a base station, a report of the distance between the reader and the Internet of things device; or means for transmitting, to a base station, a report of whether the distance meets the distance criterion. The reader may comprise: means for receiving, from a base station, an indication to determine round-trip time between the reader and the Internet of things device; or means for receiving, from a base station, an indication to determine whether a distance meets the distance criterion. The reader may comprise: a user equipment or a base station. According to an aspect there is provided a method comprising: transmitting, to an Internet of things device, a reader to device signal comprising an indication to transmit, to the reader, a device to reader signal after a pre-determined delay corresponding to a pre-determined clock count; and receiving, from the Internet of things device, a device to reader signal after the pre-determined delay. The method may be performed by a reader. The method may comprise: determining a transmission time of a reader to device signal; determining a reception time of the Internet of things device to reader signal; and determining a round trip time between the reader and the Internet of things device based on the transmission time, the reception time, and the pre-determined delay. The method may comprise: determining a distance between the reader and the Internet of things device based on the round-trip time between the reader and the Internet of things device. The method may comprise: determine that the distance meets a distance criterion; and serving the Internet of things device. The distance criterion may comprise the distance is smaller than a distance threshold. The reader may comprise: receiving, from a base station, configuration information comprising a report of the distance criterion. The configuration information may be received via radio resource control or system information block. The method may comprise: transmitting, to a base station, a report of the round-trip time between the reader and the Internet of things device; transmitting, to a base station, a report of the distance between the reader and the Internet of things device; or transmitting, to a base station, a report of whether the distance meets the distance criterion. The method may comprise: receiving, from a base station, an indication to determine round-trip time between the reader and the Internet of things device; or receiving, from a base station, an indication to determine whether a distance meets the distance criterion. The reader may comprise: a user equipment or a base station. According to an aspect there is provided a reader comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the reader at least to perform: transmitting, to an Internet of things device, a reader to device signal comprising an indication to transmit, to the reader, a device to reader signal after a pre-determined delay corresponding to a predetermined clock count; and receiving, from the Internet of things device, a device to reader signal after the pre-determined delay. According to an aspect there is provided a reader comprising circuitry configured to perform: transmitting, to an Internet of things device, a reader to device signal comprising an indication to transmit, to the reader, a device to reader signal after a pre-determined delay corresponding to a pre-determined clock count; and receiving, from the Internet of things device, a device to reader signal after the pre-determined delay. According to an aspect there is provided a computer program comprising computer executable code which when run on at least one processor is configured to perform: transmitting, to an Internet of things device, a reader to device signal comprising an indication to transmit, to the reader, a device to reader signal after a pre-determined delay corresponding to a pre-determined clock count; and receiving, from the Internet of things device, a device to reader signal after the pre-determined delay. According to an aspect there is provided an Internet of things device comprising: means for receiving, from a reader, a prior reader to device signal comprising an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a reader to device signal and transmitting, to the reader, a device to reader signal; means for transmitting, to the reader, the device to reader signal; means for determining the measured delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal; and means for transmitting, to the reader, a subsequent device to reader signal comprising a report of the measured delay. The measured delay may include an internal delay for processing at least one of a reader to device signal or a device to reader signal. The measured delay may be equal the internal delay for processing at least one of a reader to device signal or a device to reader signal. The internal delay for processing at least one of a reader to device signal or a device to reader signal may comprise a maximum internal delay for processing at least one of a reader to device signal or a device to reader signal. The internal delay for processing at least one of a reader to device signal or a device to reader signal may be set in the standards. The internal delay for processing at least one of a reader to device signal or a device to reader signal may depend on a class of the Internet of things device. That is, Internet of things devices with different classes may have different internal delays for processing at least one of a reader to device signal or a device to reader signal. Processing a reader to device signal may comprise decoding a reader to device signal Processing the device to reader signal may comprise encoding a device to reader signal for transmission. The device may comprise: means for receiving, from the reader, a subsequent reader to device signal. The subsequent device to reader signal may be transmitted in response to the subsequent reader to device signal. The means for measuring the delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal may comprise: means for triggering a clock count upon receiving, from the reader, the reader to device signal; and means for stopping the clock count upon transmitting, to the reader, the device to reader signal. The reader to device signal may comprise at least one of: a synchronisation signal; or a payload. The synchronisation signal may comprise at least one of: a delimiter; ora clock signal. The clock signal may comprise a square wave signal. The means for measuring the delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal may comprise: means for synchronising a clock signal of a clock oscillator with the synchronisation signal. The device may comprise: means for transmitting, to the reader, a prior device to reader signal comprising an indication of Internet of things device capabilities. The report of Internet of things device capabilities may comprise at least one of: whether the Internet of things device comprises a clock oscillator; an internal delay for processing at least one a reader to device signal or a device to reader signal; or a duration during which the Internet of things device maintains synchronisation between a clock signal of an oscillator and a clock signal of a synchronisation signal after receiving the clock signal of the synchronisation signal. The reader to device signal may comprise an indication that the reader to device signal is for determining a round trip time between the reader and the device; and / or the device to reader signal may comprise an indication that the device to reader signal is for determining at least one of a round trip time between the reader and the Internet of things device or a distance between the reader and the Internet of things device. The indication that the reader to device signal is for determining at least one of a round trip time between the reader and the Internet of things device or a distance between the reader and the Internet of things device may comprise a pre-determined sequence or reference signal. The Internet of things device may comprise an ambient Internet of Things device. According to an aspect there is provided a method comprising: receiving, from a reader, a prior reader to device signal comprising an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a reader to device signal and transmitting, to the reader, a device to reader signal; transmitting, to the reader, the device to reader signal; determining the measured delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal; and transmitting, to the reader, a subsequent device to reader signal comprising a report of the measured delay. The method may be performed by an Internet of things device. The measured delay may include an internal delay for processing at least one of a reader to device signal or a device to reader signal. The measured delay may be equal the internal delay for processing at least one of a reader to device signal or a device to reader signal. The internal delay for processing at least one of a reader to device signal or a device to reader signal may comprise a maximum internal delay for processing at least one of a reader to device signal or a device to reader signal. The internal delay for processing at least one of a reader to device signal or a device to reader signal may be set in the standards. The internal delay for processing at least one of a reader to device signal or a device to reader signal may depend on a class of the Internet of things device. That is, Internet of things devices with different classes may have different internal delays for processing at least one of a reader to device signal or a device to reader signal. Processing a reader to device signal may comprise decoding a reader to device signal Processing the device to reader signal may comprise encoding a device to reader signal for transmission. The method may comprise: receiving, from the reader, a subsequent reader to device signal. The subsequent device to reader signal may be transmitted in response to the subsequent reader to device signal. The measuring the delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal may comprise: triggering a clock count upon receiving, from the reader, the reader to device signal; and stopping the clock count upon transmitting, to the reader, the device to reader signal. The reader to device signal may comprise at least one of: a synchronisation signal; or a payload. The synchronisation signal may comprise at least one of: a delimiter; ora clock signal. The clock signal may comprise a square wave signal. The measuring the delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal may comprise: synchronising a clock signal of a clock oscillator with the synchronisation signal. The method may comprise: transmitting, to the reader, a prior device to reader signal comprising an indication of Internet of things device capabilities. The report of Internet of things device capabilities may comprise at least one of: whether the Internet of things device comprises a clock oscillator; an internal delay for processing at least one a reader to device signal or a device to reader signal; or a duration during which the Internet of things device maintains synchronisation between a clock signal of an oscillator and a clock signal of a synchronisation signal after receiving the clock signal of the synchronisation signal. The reader to device signal may comprise an indication that the reader to device signal is for determining a round trip time between the reader and the device; and / or the device to reader signal may comprise an indication that the device to reader signal is for determining at least one of a round trip time between the reader and the Internet of things device or a distance between the reader and the Internet of things device. The indication that the reader to device signal is for determining at least one of a round trip time between the reader and the Internet of things device or a distance between the reader and the Internet of things device may comprise a pre-determined sequence or reference signal. The Internet of things device may comprise an ambient Internet of Things device. According to an aspect there is provided an Internet of things device comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the Internet of things device at least to perform: receiving, from a reader, a prior reader to device signal comprising an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a reader to device signal and transmitting, to the reader, a device to reader signal; transmitting, to the reader, the device to reader signal; determining the measured delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal; and transmitting, to the reader, a subsequent device to reader signal comprising a report of the measured delay. According to an aspect there is provided an Internet of things device comprising circuitry configured to perform: receiving, from a reader, a prior reader to device signal comprising an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a reader to device signal and transmitting, to the reader, a device to reader signal; transmitting, to the reader, the device to reader signal; determining the measured delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal; and transmitting, to the reader, a subsequent device to reader signal comprising a report of the measured delay. According to an aspect there is provided a computer program comprising computer executable code which when run on at least one processor is configured to perform: receiving, from a reader, a prior reader to device signal comprising an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a reader to device signal and transmitting, to the reader, a device to reader signal; transmitting, to the reader, the device to reader signal; determining the measured delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal; and transmitting, to the reader, a subsequent device to reader signal comprising a report of the measured delay. According to an aspect there is provided a reader comprising: transmitting, to the reader, a device to reader signal; means for receiving, from the Internet of things device, the device to reader signal; and means for receiving, from the Internet of things device, a subsequent device to reader signal comprising a report of the measured delay. The reader may comprise: means for determining a transmission time of the reader to device signal; means for determining a reception time of the device to reader signal; means for determining a round trip time between the reader and the Internet of things device based on the transmission time, the reception time, and the measured delay. The reader may comprise: means for determining a distance between the reader and the Internet of things device based on the round-trip time between the reader and the Internet of things device. The reader may comprise: means for determine that the distance meets a distance criterion; and means for serving the Internet of things device. The distance criterion may comprise the distance is smaller than a distance threshold. The device may comprise: means for receiving, from a base station, configuration information comprising a report of the distance criterion. The configuration information may be received via radio resource control or system information block. The reader may comprise: means for transmitting, to a base station, a report of the round-trip time between the reader and the Internet of things device; means for transmitting, to a base station, a report of the distance between the reader and the Internet of things device; or means for transmitting, to a base station, a report of whether the distance meets the distance criterion. The reader may comprise: means for receiving, from a base station, an indication to determine round-trip time between the reader and the Internet of things device; or means for receiving, from a base station, an indication to determine whether a distance meets the distance criterion. The reader may comprise a user equipment or a base station. According to an aspect there is provided a method comprising: transmitting, to the reader, a device to reader signal; receiving, from the Internet of things device, the device to reader signal; and receiving, from the Internet of things device, a subsequent device to reader signal comprising a report of the measured delay. The method may be performed by a reader. The method may comprise: determining a transmission time of the reader to device signal; determining a reception time of the device to reader signal; determining a round trip time between the reader and the Internet of things device based on the transmission time, the reception time, and the measured delay. The method may comprise: means for determining a distance between the reader and the Internet of things device based on the round-trip time between the reader and the Internet of things device. The method may comprise: determine that the distance meets a distance criterion; and serving the Internet of things device. The distance criterion may comprise the distance is smaller than a distance threshold. The method may comprise: receiving, from a base station, configuration information comprising a report of the distance criterion. The configuration information may be received via radio resource control or system information block. The method may comprise: transmitting, to a base station, a report of the round-trip time between the reader and the Internet of things device; transmitting, to a base station, a report of the distance between the reader and the Internet of things device; or transmitting, to a base station, a report of whether the distance meets the distance criterion. The method may comprise: receiving, from a base station, an indication to determine round-trip time between the reader and the Internet of things device; or receiving, from a base station, an indication to determine whether a distance meets the distance criterion. The reader may comprise a user equipment or a base station. According to an aspect there is provided a reader comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the reader at least to perform: transmitting, to the reader, a device to reader signal; receiving, from the Internet of things device, the device to reader signal; and receiving, from the Internet of things device, a subsequent device to reader signal comprising a report of the measured delay. According to an aspect there is provided a reader comprising circuitry configured to perform: transmitting, to the reader, a device to reader signal; receiving, from the Internet of things device, the device to reader signal; and receiving, from the Internet of things device, a subsequent device to reader signal comprising a report of the measured delay. According to an aspect there is provided a computer program comprising computer executable code which when run on at least one processor is configured to perform: transmitting, to the reader, a device to reader signal; receiving, from the Internet of things device, the device to reader signal; and receiving, from the Internet of things device, a subsequent device to reader signal comprising a report of the measured delay. According to an aspect, there is provided a computer readable medium comprising program instructions stored thereon for performing at least one of the above methods. According to an aspect, there is provided a non-transitory computer readable medium comprising program instructions stored thereon for performing at least one of the above methods. According to an aspect, there is provided a non-volatile tangible memory medium comprising program instructions stored thereon for performing at least one of the above methods. In the above, many different aspects have been described. It should be appreciated that further aspects may be provided by the combination of any two or more of the aspects described above. Various other aspects are also described in the following detailed description and in the attached claims. List of abbreviations AF: Application Function A-loT: Ambient Internet of Things AMF: Access and Mobility Management Function BS: Base Station CU: Centralized Unit D2R: Device to Reader DL: Downlink DU: Distributed Unit gNB: gNodeB loT: Internet of Things LTE: Long Term Evolution MS: Mobile Station MTC: Machine Type Communication NEF: Network Exposure Function NF: Network Function NR: New radio NRF: Network Repository Function PDRCH: Physical Device to Reader Channel PRDCH: Physical Reader to Device Channel R2D: Reader to Device RAM: Random Access Memory (R)AN: (Radio) Access Network ROM: Read Only Memory SMF: Session Management Function UE: User Equipment 4G: 4th Generation 5G: 5th Generation 5GC: 5G Core network 5GS: 5G System 6G: 6th Generation Brief Description of the Figures Embodiments will now be described, by way of example only, with reference to the accompanying Figures in which: Fig. 1 shows a schematic representation of an example 5G system; Fig. 2 shows a schematic representation of an example control apparatus; Fig. 3 shows a schematic representation of an example user equipment; Fig. 4 shows a schematic representation of an example of a transmission of a reader to device signal and a transmission of a device to reader signal; Fig. 5 shows a schematic representation of an example of transmissions of reader to device signals and transmissions of device to reader signals; Fig. 6 shows a signaling diagram of an example of a process for managing an ambient Internet of Things device performed by an ambient Internet of Things device, a reader and a base station); Fig. 7 shows a block diagram of an example of a method for managing an ambient Internet of Things device performed by the ambient Internet of Things device; Fig. 8 shows a block diagram of an example of a method for managing an ambient Internet of Things device performed by a reader; Fig. 9 shows a block diagram of an example of a method for managing an ambient Internet of Things device performed by the ambient Internet of Things device; Fig. 10 shows a block diagram of an example of a method for managing an ambient Internet of Things device performed by a reader); Fig. 11 shows a schematic representation of a non-volatile memory medium storing instructions which when executed by a processor allow a processor to perform one or more of the steps of the method of any of Fig. 7 to Fig. 10. Detailed Description of the Figures In the following certain embodiments are explained with reference to mobile communication devices capable of communication via a wireless cellular system and mobile communication systems serving such mobile communication devices. Before explaining in detail the exemplifying embodiments, certain general principles of a wireless communication system, access systems thereof, and mobile communication devices are briefly explained with reference to Fig. 1, Fig.2 and Fig.3 to assist in understanding the technology underlying the described examples. FIG. 1 shows a schematic representation of an example 5G system (5GS). The 5GS may comprises Internet of things (loT) devices, user equipment (UEs), a (radio) access network ((R)AN), a 5G core network (5GC), one or more application functions (AF) and one or more data networks (DN). The loT devices may comprise ambient loT (A-loT) devices. An A-loT device may be configured to measure ambient conditions, such as location, temperature, pressure, noise, light or other ambient conditions. An A-loT device may comprise a sensor. An A-loT device may be configured to harvest energy (e.g., radio frequency energy from a signal received from another apparatus or solar energy). The UEs may comprise activator UEs, reader UEs or activator and reader UEs. An activator UE may be configured to transmit an activation signal to an A-loT device to trigger the A-loT device to transmit a response signal to a reader UE. A reader UE may be configured to receive a response signal from an A-loT device and to transmit a report signal to the 5G(R)AN. In this disclosure, the expressions “activation signal”, “illumination signal” and “incident signal” may be used interchangeably. In this disclosure, the expressions “response signal”, “backscattered signal” or “reflected signal” may be used interchangeably. The 5G (R)AN may comprise one or more gNodeBs (gNBs). The gNodeBs may comprise one or more gNB distributed unit functions connected to one or more gNB centralized unit functions. The gNodeBs may comprise activator gNodeBs, reader gNodeBs or activator and reader gNodeBs. The 5GC may comprise an access and mobility management function (AMF), a session management function (SMF), an authentication server function (ALISF), a user data management (UDM), a user plane function (UPF), a network exposure function (NEF). Fig. 2 illustrates an example of a control apparatus 200 for controlling a function of the (R)AN or the 5GC as illustrated on Fig. 1. The control apparatus may comprise at least one random access memory (RAM) 211a, at least on read only memory (ROM) 211b, at least one processor 212, 213 and an input / output interface 214. The at least one processor 212,213 may be coupled to the RAM 211a and the ROM 211 b. The at least one processor 212, 213 may be configured to execute an appropriate software code 215. The software code 215 may for example allow to perform one or more steps to perform one or more of the present aspects. The software code 215 may be stored in the ROM 211b. The control apparatus 200 may be interconnected with another control apparatus 200 controlling another function of the 5G (R)AN or the 5GC. In some embodiments, each function of the (R)AN or the 5GC comprises a control apparatus 200. In alternative embodiments, two or more functions of the (R)AN or the 5GC may share a control apparatus. Fig. 3 illustrates an example of a user equipment 300, such as the terminal illustrated on Fig. 1. The UE 300 may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a user equipment, a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), a personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine-type communications (MTC) device, a Cellular Internet of things (CloT) device or any combinations of these or the like. The UE 300 may provide, for example, communication of data for carrying communications. The communications may be one or more of voice, electronic mail (email), text message, multimedia, data, machine data and so on. The UE 300 may receive signals over an air or radio interface 307 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Fig. 3 transceiver apparatus is designated schematically by block 306. The transceiver apparatus 306 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device. The UE 300 may be provided with at least one processor 301, at least one memory ROM 302a, at least one RAM 302b and other possible components 303 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The at least one processor 301 is coupled to the RAM 302b and the ROM 302a. The at least one processor 301 may be configured to execute an appropriate software code 308. The software code 308 may for example allow to perform one or more of the present aspects. The software code 308 may be stored in the ROM 302a. The processor, storage and other relevant control apparatus can be provided on an appropriate circuit board and / or in chipsets. This feature is denoted by reference 304. The device may optionally have a user interface such as keypad 305, touch sensitive screen or pad, combinations thereof or the like. Optionally one or more of a display, a speaker and a microphone may be provided depending on the type of the device. One or more aspect of this disclosure relates to managing an A-loT device, in particular to determine a distance between the A-loT device and a reader. Various techniques have been proposed to determine the distance between an A-loT device and a reader. For example, the reader may transmit, to the A-loT device, a reader to device (R2D) signal. The A-loT device may transmit (e.g., backscatter), to the reader, a device to reader (D2R) signal. The reader may transmit the R2D signal at a transmission time Tx. The reader may receive the D2R signal at a reception time Rx. The reader may determine a round-trip time between the reader and the A-loT device based on the transmission time and the reception time. The reader may determine a distance (e.g., proximity) between the reader and the A-loT device based on the round-trip time. If the distance meets a distance criterion (e.g., proximity criterion) the reader may subsequently serve (e.g., support) the A-loT device. If the distance does not meet a distance criterion (e.g., proximity criterion) the reader may not subsequently serve (e.g., support) the A-loT device. The distance criterion may comprise the distance being smaller than a distance threshold. Alternatively or additionally, the reader may determine a distance (e.g., proximity) between the reader and the A-loT device based on a measurement (e.g., power measurement) of the D2R signal. The distance criterion may comprise the measurement of the D2R signal being greater than a measurement threshold (e.g. power threshold). A problem with such technique is that it does not take into consideration the internal delay at the A-loT for processing the R2D signal (e.g., decoding a payload of the R2D signal) and / or for processing the D2R signal (e.g., encoding (e.g., and preparing) a payload of the D2R). Such internal delay may depend on the A-loT device. Such internal delay may depend on the size (e.g., length) of the R2D signal and the D2R signal. As a result, the distance determined by the reader based on the round-trip time may be inaccurate. One or more aspect of this disclosure provides a mechanism for managing an A-loT device, in particular but not exclusively, to address the above problem. It will be understood that although the mechanism for managing an A-loT device is discussed in the context of an A-loT device, the mechanism may be used with an loT device. It will be understood that although the mechanism for managing an A-loT device is discussed in the context of determining the distance (e.g., proximity) between the reader and the A-loT device, the mechanism may be used with other applications. For example, the mechanism may be used to schedule transmissions of D2R signals (e.g., data). To avoid interference issues or simultaneous transmissions of D2R signals (e.g., data) from A-loT devices, the reader may want to schedule transmissions of D2R signals at specific transmission times. The reader may transmit, to a A-loT device, a R2D signal comprising a indication to transmit a D2R signal after a pre-determined delay corresponding to a pre-determined clock count or after a measured delay corresponding to a measured clock count. It will be understood that although the mechanism for managing an A-loT device is discussed in the context of a 5GS, the mechanism may be used with other communication systems. Fig. 5 shows a schematic representation of an example of the transmissions of a R2D signal #1, the transmission of the D2R signal #1, the transmission of the R2D signal #2 and the transmission of the D2R signal #2 in a process for managing an A-loT device discussed below. Fig. 6 shows a signaling diagram of an example of a process for managing an A-loT device performed by an A-loT device, a reader and a BS in a process for managing an A-loT device discussed below. At step S1, a BS (e.g., gNB) may transmit, to a reader (e.g., UE), a resource allocation for communication between the reader and an A-loT device. It will be understood that if the reader is not necessarily a UE. If the reader is a BS, the reader may not receive configuration information from another BS. The reader may determine the resource allocation. At step S2, the BS may transmit, to the reader, configuration information for determining the distance between the reader and the A-loT device. The configuration may be transmitted via radio resource control. The configuration information may be UE-specific configuration information provided by the BS. In this way, multiple readers may receive different configuration information. The configuration may be transmitted (e.g., broadcast) via system information block. In this way, multiple readers may receive the same configuration information. The configuration information may comprise a distance criterion (e.g., proximity criterion). The distance criterion may be based on a distance threshold. The distance criterion may comprise a distance between the reader and the A-loT device being smaller than a distance threshold. The configuration information may comprise a request to receive, from an A-loT device, A-loT device capabilities. The A-loT device capabilities may comprise whether the A-loT device comprises a clock oscillator. The A-loT device capabilities may comprise an internal delay for processing a R2D signal and / or for processing a D2R signal. The A-loT device capabilities may comprise a duration during which the A-loT device maintains synchronisation (e.g., perform clock tracking) between a clock signal of an oscillator and a clock signal of a synchronisation signal after receiving the clock signal of a synchronisation signal (i.e., e.g., without receiving the clock signal of a synchronisation signal). The reader may use the A-loT device capabilities to determine whether to use a first option, a second option or none of the first option and second option to determine a distance between the reader and the A-loT device. It will be understood that if the reader is a BS, the reader may not receive configuration information from another BS. The reader may determine the configuration information. At step S3, the reader may transmit, to the A-loT device, a R2D signal #0. The R2D signal #0 may comprise an activation signal. The R2D signal #0 may comprise an indication to transmit, to the reader, A-loT device capabilities. The indication may be conveyed in a payload of the R2D signal #0. The payload may be conveyed in a physical reader to device channel (PRDCH). At step S4, the A-loT device may transmit (e.g., backscatter), to the reader, a D2R signal #0. The D2R signal #0 may comprise a report of (e.g., indication of) acknowledgement of reception of the R2D signal #0. The D2R signal #0 may comprise a report of (e.g., indication of) A-loT device capabilities. The indications may be conveyed in a payload of the D2R #0. The payload may be conveyed in a physical device to reader channel (PDRCH). At step S5, the reader may transmit, to the A-loT device, a R2D signal #1. In a first option, the R2D signal #1 may comprise an indication to transmit, to the reader, a D2R signal #N after a pre-determined delay corresponding to a predetermined clock count from receiving a R2D signal #N (i.e., an indication to wait for a pre-determined delay from receiving a R2D signal #N before transmitting, to the reader, a D2R signal #N). The R2D signal #1 may comprise a report of (e.g., indication of) the R2D signal #N and the D2R signal #N (e.g., R2D signal #2 and D2R signal #2). The indications may be conveyed in a payload of the R2D signal #1. The payload may be conveyed in a PRDCH. It will be understood that the pre-determined delay is bounded by receiving the R2D signal #N (i.e., initiated / triggered by receiving the R2D signal #N) and transmitting, to the reader, the D2R signal #N (i.e., stopped by transmitting the D2R signal #N). The pre-determined delay may be from receiving the end of the R2D signal #N (e.g., receiving the end of the payload of the R2D signal #N) and transmitting the beginning of the D2R signal #N (e.g. transmitting the beginning of the payload of the D2R signal #N). The pre-determined delay may comprise a clock count. The pre-determined delay may be different from the internal delay for processing the R2D signal #N and / or for processing the D2R signal #N of the A-loT device. The internal delay for processing the R2D signal #N and / or for processing a D2R signal #N may comprise a maximum internal delay for processing the R2D signal #N and / or for processing the D2R signal #N. The payload of the R2D signal #N and / or for processing the D2R signal #N may have a specific size (e.g., length). The pre-determined delay may be equal to or greater than the internal delay for processing the R2D signal #N and / or for processing a D2R signal #N of the A-loT device (alternative 1). The R2D signal #1 may comprise a report of (e.g., indication of) the pre-determined delay. The indication may be conveyed in the payload of the R2D signal #1. The pre-determined delay may be configured at the A-loT device and the reader. The pre-determined delay may be set in the standards. The internal delay for processing the R2D signal #N and / or for processing the D2R signal #N may depend on a class of the A-loT device. That is, A-loT devices with different classes may have different internal delays for processing the R2D signal #N and / or for processing the D2R signal #N. The standards may specify different pre-determined delays for different classes. The pre-determined delay may be lower than the internal delay for processing the R2D signal #N and / or for processing a D2R signal #N of the A-loT device (alternative 2). In a second option, the R2D signal #1 may comprise an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a R2D signal #N and transmitting, to the reader, an D2R signal #N. The R2D signal #1 may comprise a report of (e.g., indication of) the R2D signal #N and the D2R signal #N (e.g., R2D signal #2 and D2R signal #2) used to measure the delay. The measured delay may include the internal delay for processing the R2D signal #N and / or for processing a D2R signal #N of the A-loT device. The measured delay may be equal to the internal delay for processing the R2D signal #N and / or for processing a D2R signal #N of the A-loT device. The measured delay may be from receiving the end of the R2D signal #N (e.g., receiving the end of the payload of the R2D signal #N) and transmitting the beginning of the D2R signal #N (e.g. transmitting the beginning of the payload of the D2R signal #N). The R2D signal #1 may comprise an indication to transmit the measured delay on a D2R signal #K. The R2D signal #1 may comprise a report of (e.g., indication of) the D2R signal #K (e.g., D2R signal #3) used to transmit a report of (e.g., indication of) the measured delay. The indications may be conveyed in a payload of the R2D signal #1. The payload may be conveyed in a PRDCH. At step S6 (see Fig. 5), the A-loT device may transmit (e.g., backscatter), to the reader, a D2R signal #1. The D2R signal #1 may comprise a report of (e.g., indication of) acknowledgement of reception of the R2D signal #1. The indication may be conveyed in a payload of the D2R signal #1. The payload may be conveyed in a PDRCH. It will be understood that the R2D signal #1 may not comprise a report of (e.g., indication of) the R2D signal #N and the D2R signal #N used to measure the delay. In this case, the D2R signal #1 may comprise a report of (e.g., indication of) the R2D signal #N and the D2R signal #N. The indication may be conveyed in a payload of the D2R signal #1. The payload may be conveyed in a PDRCH. In the first option, when the pre-determined delay is lower than the internal delay for processing the R2D signal #N and / or for processing a D2R signal #N of the A-loT device, the D2R signal #1 may comprise an indication to extend the pre-determined delay. The indication may be conveyed in the payload of the D2R signal #1. It may be understood that the A-loT device may be able to transmit the indication to extend the pre-determined delay after the pre-determined delay since transmitting the indication to extend the pre-determined delay can be performed with minimal processing and signal preparation (e.g., it may comprise transmitting a pre-determined signal such as a preamble or a signal modulated with a flag). In a scenario, the D2R signal #1 may comprise a report of (e.g., indication of) a requested (desired) extension of the pre-determined delay. The indication may be conveyed in the payload of the D2R signal #1. The indication of the requested extension may comprise an indication of an additional clock count. In such scenario, the A-loT device may extend the pre-determined delay based on the requested extension if the requested extension is granted by the reader. At step S7, the reader may transmit, to the A-loT device, a R2D signal #2. The R2D signal #2 may comprise a synchronisation signal. The synchronisation signal may comprise a delimiter (e.g., start indication) and a clock signal. The clock signal may comprise a square wave signal. The square wave signal may be modulated (e.g., via amplitude shift keying). The R2D signal #2 may comprise a payload (e.g., control and / or data). The payload may be conveyed in a PRDCH. It will be understood that the R2D signal #2 may comprise more than one synchronisation signal and more than one payload. The payloads may be interleaved with synchronisation signals (e.g., preamble and midamble synchronisation signals). In this way, if the A-loT device easily loses synchronisation after synchronising with a synchronisation signal, the A-loT device may re-synchronise with another synchronisation signal. This may ensure that all payloads are successfully decoded. In the first option, when the pre-determined delay is lower than the internal delay for processing the R2D signal #N and / or for processing a D2R signal #N of the A-loT device (alternative 2a), the R2D signal #2 may comprise a report of (e.g., indication of) an extension of the pre-determined delay. The extension of the pre-determined delay may comprise an additional clock count. The A-loT device may extend the predetermined delay based on the extension of the pre-determined delay. Alternatively, the R2D signal #2 may not comprise a report of (e.g., indication of) an extension of the pre-determined delay (failure). Alternatively, the R2D signal #2 may not comprise a report of (e.g., indication of) grant of a requested extension of the pre-determined delay (failure). Alternatively, the R2D signal #2 may comprise a report of (e.g., indication of) grant of a requested extension of the pre-determined delay. At step S8. the A-loT device may detect the start of the clock signal based on the delimiter. The A-loT device may harvest power based on the clock signal. The A-loT device may synchronise a clock signal of a clock oscillator with the clock signal. The A-loT device may trigger a clock count upon receiving the payload of the R2D signal #2. The A-loT device may trigger a clock count upon receiving the beginning of the payload of the R2D signal #2. The A-loT device may perform the clock count by detecting transitions or edges (e.g., rising or falling edges) of the clock signal and updating (e.g., incrementing or decrementing) a counter. The A-loT device may decode the payload based on the clock of the clock oscillator. In an example, the A-loT device may use Manchester coding. The A-loT device may determine a chip length in the synchronisation signal. The A-loT device may sample and decode bits of the payload by detecting edges based on the clock of the clock oscillator and the chip length. The A-loT device may perform time tracking / time adjustments with chip-level as it knows the chip length and boundary of bits. At step S9, the A-loT device may transmit (e.g., backscatter), to the reader a D2R signal #2. The A-loT device may transmit, to the reader a D2R signal #2 based on the clock signal of the clock oscillator. In the first option, the A-loT device may determine that the clock count has reached (i.e., reaches) the pre-determined clock count corresponding to the pre-determined delay (e.g., wait until the clock count has reached (i.e., reaches) the pre-determined clock count corresponding to the pre-determined delay) and may then transmit the D2R signal #2. The D2R signal #2 may comprise a report of (e.g., indication of) acknowledgement of reception of the R2D signal #2. The indications may be conveyed in a payload of the D2R signal #2. The payload may be conveyed in a PDRCH. In the first option, when the pre-determined delay is lower than the internal delay for processing the R2D signal #N and / or for processing a D2R signal #N of the A-loT device (alternative 2b), the R2D signal #2 may comprise a report of (e.g., indication of) an extension of the pre-determined delay. The A-loT device may determine that the extension of the pre-determined delay is the reported extension of the predetermined delay. In the first option, when the pre-determined delay is lower than the internal delay for processing the R2D signal #N and / or for processing a D2R signal #N of the A-loT device (alternative 2b), the R2D signal #2 may comprise a report of (e.g., indication of) grant of a requested extension of the pre-determined delay. The A-loT device may determine that the extension of the pre-determined delay is the requested extension of the pre-determined delay. In the first option, when the pre-determined delay is lower than the internal delay for processing the R2D signal #N and / or for processing a D2R signal #N of the A-loT device (alternative 2b), the R2D signal #2 may not comprise a report of (e.g., indication of) an extension of the pre-determined delay. The R2D signal #2 may not comprise a report of (e.g., indication of) grant of a requested extension of the pre-determined delay. The A-loT device may fail to determine the extension of the pre-determined delay. In such scenario, the A-loT device may not extend the pre-determined delay. The A-loT device may not transmit, to the reader, the D2R signal #2. In the second option, the A-loT device may transmit (e.g., backscatter) the D2R signal #2. The A-loT device may stop the clock count upon transmitting the payload of the D2R signal #2. The A-loT device may stop the clock count upon transmitting the beginning of the payload of the D2R signal #2. The D2R signal #2 may comprise a report of (e.g., indication of) acknowledgement of reception of the R2D signal #2. The D2R signal #2 may comprise an indication (e.g., sequence or reference signal) that the D2R signal #2 is for determining a round-trip time between the reader and the A-loT device. The indications may be conveyed in a payload of the D2R signal #2. The payload may be conveyed in a PDRCH. At step 10, the reader may transmit, to the A-loT device, a R2D signal #3. At step 11, The A-loT device may transmit (e.g., backscatter), to the reader a D2R signal #3. The D2R signal #3 may comprise a report of (e.g., indication of) acknowledgement of reception of the R2D signal #3. The D2R signal #3 may comprise a report of (e.g., indication of) the clock count. The indication may be conveyed in a payload of the D2R signal #2. The payload may be conveyed in a PDRCH. It will be understood that the clock count is stopped upon transmitting the D2R signal #2. Accordingly, the report of (e.g., indication of) the clock count cannot be conveyed in the payload of the D2R signal #2 but is conveyed in the payload of the D2R #3. The A-loT device may need processing time to encode the clock count, so the payload may be transmitted in the payload of the D2R#3. It will be understood that in case of failure the A-loT device may not transmit (e.g., backscatter), to the reader, the D2R signal #3. At step S12, the reader may determine a transmission time of the R2D #2. The reader may determine a reception time of the D2R #2. The reader may determine a roundtrip time between the reader and the A-loT device based on the transmission time of the R2D #2 and the reception time of the D2R #2. In the first option, the reader may determine a round-trip time between the reader and the A-loT device based on the transmission time of the R2D #2, the reception time of the D2R #2 and the pre-determined delay. For example, the reader may determine the round-trip time between the reader and the A-loT device as follows: Ti = TRx-TTx - (1) Where T± is the round-trip time between the reader and the A-loT device, TRx is the reception time of the D2R transmission #2, TTx is the transmission time of the R2D #2, and x1 is the pre-determined delay. As an example, more specifically, x1 is a time difference between the end of the reception of the R2D signal (R2D #2) and the start of the transmission of D2R signal (D2R #2). The A-loT device may not be able to perform cross-correlation operation to measure x1, so it may perform clock counting to measure or estimate x1. In the second option, the reader may determine the measured delay based on the clock count. The reader may determine a round-trip time between the reader and the A-loT device based on the transmission time of the R2D #2, the reception time of the D2R #2 and the measured delay. For example, the reader may determine the roundtrip time between the reader and the A-loT device as follows: — TRx TTx x2 (2) Where T2 is the round-trip time between the reader and the A-loT device, TRx is the reception time of the D2R transmission #2, TTx is the transmission time of the R2D #2, and X2 is the pre-determined delay. At step S13, the reader may determine the distance (e.g., proximity) between the reader and the A-loT device based on the round-trip time between the reader and the A-loT device. The reader may determine whether the distance (e.g., proximity) meets the distance criterion (e.g., proximity criterion). If the distance (e.g., proximity) meets the distance criterion (e.g., proximity criterion), the reader may subsequently serve (e.g., support) the A-loT device (e.g., for data communication). If the distance (e.g., proximity) does not meet the distance criterion (e.g., proximity criterion), the reader may subsequently not serve (e.g., not support) the A-loT device (e.g., for data communication). In an implementation, the reader may also determine the distance (e.g., proximity) between the reader and the A-loT device based on a measurement (e.g., power measurement) of the D2R signal. The distance criterion (e.g., proximity criterion) may also comprise the measurement of the D2R signal being greater than a measurement threshold (e.g. power threshold). At step S14, the reader may transmit, to the BS, a report of (e.g., indication of) the round-trip time between the reader and the A-loT device, a report of (e.g., indication of) the distance between the reader and the A-loT device and / or an indication that the distance meets the distance criterion. In this way, if the BS provided resource allocation to multiple readers to communicate with multiple A-loT devices, the BS may update the resource allocation so that resource allocation is only provided to readers serving an A-loT device. It will be understood that if the reader is a BS, the reader may not transmit, to another BS, a report of (e.g., indication of) the round-trip time between the reader and the A-loT device, a report of (e.g., indication of) the distance between the reader and the A-loT device and / or an indication that the distance meets the distance criterion. The reader may update the resource allocation. It will be understood that although in the above, in the second embodiment, the A-loT device transmits, to the reader, a D2R signal #N+1 comprising a report of (e.g., indication of) a measured delay between receiving a R2D signal #N and transmitting a D2R signal #N once, the A-loT device may transmit, to the reader, a D2R signal #N+1 comprising a report of (e.g., indication of) a measured delay between receiving a R2D signal #N and transmitting a D2R signal #N multiple times (e.g., until indicated otherwise by the reader). For example, the A-loT device may transmit, to the reader, a D2R signal #3 comprising a report of (e.g., indication of) a measured delay between receiving a R2D signal #2 and transmitting a D2R signal #2, may transmit, to the reader, a D2R signal #4 comprising a report of (e.g., indication of) a measured delay between receiving a R2D signal #3 and transmitting a D2R signal #3, may transmit, to the reader, a D2R signal #5 comprising a report of (e.g., indication of) a measured delay between receiving a R2D signal #4 and transmitting a D2R signal #4 and so on (e.g., until indicated otherwise by the reader). For example, if the A-loT device is failed to transmit an indicated pre-determined delay, the AloT device may transmit, to the reader, a report (e.g., indication of) a measured delay, which is a different pre-determined delay than the indicated pre-determined delay. It will be understood that although in the above, in the second embodiment, the A-loT device is capable of measuring a delay between receiving a R2D signal #N and transmitting a D2R signal #N, the A-loT device may fail to measure a delay between receiving a R2D signal #N and transmitting a D2R signal #N. The A-loT device may transmit, to the reader, a D2R signal #N+1 comprising a report of (e.g., indication of) a failure to measure the delay between receiving a R2D signal #N and transmitting a D2R signal #N and / or a reason for the failure. Fig. 4 shows a schematic representation of an example of the transmission of the R2D signal #2 and the transmission of the D2R signal #2 as discussed above. Fig. 7 shows a block diagram of an example of a method for managing an A-loT device performed by the A-loT device. At step 700, theA-loT device may receive, from a reader, a R2D signal comprising an indication to transmit, to the reader, a D2R signal after a pre-determined delay corresponding to a pre-determined clock count. At step 702, theA-loT device may transmit, to the reader, a D2R signal after the predetermined delay. Fig. 8 shows a block diagram of an example of a method for managing an A-loT device performed by a reader. At step 800, the reader may transmit, to an A-loT device, a R2D signal comprising an indication to transmit, to the reader, a D2R signal after a pre-determined delay corresponding to a pre-determined clock count. At step 802, the reader may receive, from the A-loT device, a D2R signal after the predetermined delay. Fig. 9 shows a block diagram of an example of a method for managing an A-loT device performed by the A-loT device. At step 900, the A-loT device may receive, from a reader, a prior R2D signal comprising an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a R2D signal and transmitting, to the reader, a D2R signal. At step 902, the A-loT device may transmit, to the reader, the D2R signal. At step 904, the A-loT device may determine the measured delay between receiving, from the reader, the R2D signal and transmitting, to the reader, the D2R signal. At step 906, the A-loT device may transmit, to the reader, a subsequent D2R signal comprising a report of the measured delay. Fig. 10 shows a block diagram of an example of a method for managing an A-loT device performed by a reader. At step 1000, the reader may transmit, to an A-loT device, a prior R2D signal comprising an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a R2D signal and transmitting, to the reader, a D2R signal. At step 1002, the reader may receive, from the A-loT device, the D2R signal. At step 1004, the reader may receive, from the A-loT device, a subsequent D2R signal comprising a report of the measured delay. Fig. 11 shows a schematic representation of non-volatile memory media 1000 storing instructions which when executed by a processor allow the processor to perform one or more of the steps of the method of any of Fig. 7 to 10. It is noted that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention. It will be understood that although the above concepts have been discussed in the context of a 5GS, one or more of these concepts may be applied to other cellular systems. The embodiments may thus vary within the scope of the attached claims. In general, some embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although embodiments are not limited thereto. While various embodiments may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. The embodiments may be implemented by computer software stored in a memory and executable by at least one data processor of the involved entities or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any procedures, e.g., as in any of Fig. 7 to Fig. 10, may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), gate level circuits and processors based on multi-core processor architecture, as non-limiting examples. Alternatively or additionally some embodiments may be implemented using circuitry. The circuitry may be configured to perform one or more of the functions and / or method steps previously described. That circuitry may be provided in the base station and / or in the communications device. As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit options (such as options in only analogue and / or digital circuitry); (b) combinations of hardware circuits and software, such as: (i) a combination of analogue and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as the communications device or base station to perform the various functions previously described; and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an option of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example integrated device. The term “means” as used in the description and in the claims may refer to one or more individual elements configured to perform the corresponding recited functionality or functionalities, or it may refer to several elements that perform such functionality or functionalities. Furthermore, several functionalities recited in the claims may be performed by the same individual means or the same combination of means. For example, performing such functionality or functionalities may be caused in an apparatus by a processor that executes instructions stored in a memory of the apparatus. The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of some embodiments However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings will still fall within the scope as defined in the appended claims.

Claims

1. An Internet of things device comprising:means for receiving, from a reader, a prior reader to device signal comprising an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a reader to device signal and transmitting, to the reader, a device to reader signal;means for transmitting, to the reader, the device to reader signal;means for determining the measured delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal; andmeans for transmitting, to the reader, a subsequent device to reader signal comprising a report of the measured delay.

2. The Internet of things device of claim 1, wherein the measured delay includes an internal delay for processing at least one of a reader to device signal or a device to reader signal.

3. The Internet of things device of claim 1 or claim 2, comprising:means for receiving, from the reader, a subsequent reader to device signal.

4. The Internet of things device of any of claims 1 to 3, wherein the means for measuring the delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal comprises:means for triggering a clock count upon receiving, from the reader, the reader to device signal; andmeans for stopping the clock count upon transmitting, to the reader, the device to reader signal.

5. The Internet of things device of any of claims 1 to 4, wherein the reader to device signal comprises at least one of:a synchronisation signal; ora payload.

6. The Internet of things device of claim 5, wherein the means for measuring the delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal comprises:means for synchronising a clock signal of a clock oscillator with the synchronisation signal.

7. The Internet of things device of any of claims 1 to 6, wherein the device comprises:means for transmitting, to the reader, a prior device to reader signal comprising an indication of Internet of things device capabilities.

8. The Internet of things device of claim 7, wherein the report of Internet of things device capabilities comprises at least one of:whether the Internet of things device comprises a clock oscillator;an internal delay for processing at least one a reader to device signal or a device to reader signal; ora duration during which the Internet of things device maintains synchronisation between a clock signal of an oscillator and a clock signal of a synchronisation signal after receiving the clock signal of the synchronisation signal.

9. The Internet of things device of any of claims 1 to 8, wherein the reader to device signal comprises an indication that the reader to device signal is for determining a round trip time between the reader and the device; and / orwherein the device to reader signal comprises an indication that the device to reader signal is for determining at least one of a round trip time between the reader and the Internet of things device or a distance between the reader and the Internet of things device.

10. A reader comprising:means for transmitting, to an Internet of things device, a prior reader to device signal comprising an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a reader to device signal and transmitting, to the reader, a device to reader signal;means for receiving, from the Internet of things device, the device to reader signal; andmeans for receiving, from the Internet of things device, a subsequent device to reader signal comprising a report of the measured delay.

11. The reader of claim 10, comprisingmeans for determining a transmission time of the reader to device signal;means for determining a reception time of the device to reader signal; andmeans for determining a round trip time between the reader and the Internet of things device based on the transmission time, the reception time, and the measured delay.

12. The reader of claim 11, comprising:means for determining a distance between the reader and the Internet of things device based on the round-trip time between the reader and the Internet of things device.

13. The reader of claim 12, comprising:means for determine that the distance meets a distance criterion; andmeans for serving the Internet of things device.

14. The reader of claim 12 or claim 13, comprising:means for transmitting, to a base station, a report of the round-trip time between the reader and the Internet of things device;means for transmitting, to a base station, a report of the distance between the reader and the Internet of things device; ormeans for transmitting, to a base station, a report of whether the distance meets the distance criterion.

15. The reader of any of claims 10 to 14, comprising:means for receiving, from a base station, an indication to determine round-trip time between the reader and the Internet of things device; ormeans for receiving, from a base station, an indication to determine whether a distance meets the distance criterion.

16. The reader of any of claims 10 to 15, wherein the reader comprises a user equipment or a base station.

17. A method comprising:receiving, from a reader, a prior reader to device signal comprising an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a reader to device signal and transmitting, to the reader, a device to reader signal;transmitting, to the reader, the device to reader signal;determining the measured delay between receiving, from the reader, the reader to device signal and transmitting, to the reader, the device to reader signal; and means for transmitting, to the reader, a subsequent device to reader signal comprising a report of the measured delay.

18. A method comprising:transmitting, to an Internet of things device, a prior reader to device signal comprising an indication to determine a measured delay corresponding to a measured clock count between receiving, from the reader, a reader to device signal and transmitting, to the reader, a device to reader signal;receiving, from the Internet of things device, the device to reader signal; andreceiving, from the Internet of things device, a subsequent device to reader signal comprising a report of the measured delay.1519. A computer program product comprising computer executable instructions which when run on one or more processors perform the steps of the method of any of claims 17 and 18.

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