Method performed by reader device, method performed by mobile device, reader device and mobile device

Abstract

An aspect of this disclosure includes a method performed by a reader device. The method includes transmitting, to a mobile device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled.

Description

METHOD PERFORMED BY READER DEVICE, METHOD PERFORMED BY MOBILE DEVICE, READER DEVICE AND MOBILE DEVICE

[0001] The present disclosure relates to a communication system and to parts thereof.

[0002] The disclosure has particular but not exclusive relevance to wireless communication systems and devices thereof operating according to the 3rd Generation Partnership Project (3GPP) standards, equivalents, or derivatives thereof (including Long Term Evolution (LTE)-Advanced, Next Generation or 5G networks, future generations, and beyond). The present disclosure relates, in particular but not exclusively, to an 'Ambient' Internet-of-Things (IoT) system with one or more (potentially multiple) A-IoT devices operating in a duty-cycle manner that are configured to operate in 'ON', 'OFF', and / or 'SLEEP' states.

[0003] Earlier developments of the 3GPP standards were referred to as the Long-Term Evolution (LTE) of Evolved Packet Core (EPC) network and Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), also commonly referred as '4G'. More recently, the term '5G' and 'new radio' (NR) is used to refer to an evolving communication technology that supports a variety of applications and services. Various details of 5G networks are described in, for example, the 'NGMN 5G White Paper' V1.0 by the Next Generation Mobile Networks (NGMN) Alliance, which document is available from https: / / www.ngmn.org / 5g-white-paper.html. 3GPP intends to support 5G by way of the so-called 3GPP Next Generation (NextGen) radio access network (RAN) and the 3GPP NextGen core network.

[0004] Under the 3GPP standards, a NodeB (or an eNB in LTE, and gNB in 5G) is the radio access network (RAN) node (or simply 'access node', 'access network node' or 'base station') via which communication devices (user equipments or 'UEs') connect to a core network and communicate with other communication devices or remote servers. For simplicity, the present application may use the term access network node, RAN node (or simply RAN) or base station to refer to any such access nodes.

[0005] For simplicity, the present application will use the term mobile device, user device, UE, or IoT device, to refer to any communication device that is able to connect to the core network via one or more base stations. Although the present application may refer to mobile devices in the description, it will be appreciated that the technology described can be implemented on any communication devices (mobile and / or generally stationary) that can connect to a communication network for sending / receiving data, regardless of whether such communication devices are controlled by human input or software instructions stored in memory. An IoT device may, for example, be any UE equipped with appropriate electronics, software, sensors, network connectivity, and / or the like, which enable these devices to collect and exchange data with each other and with other communication devices. IoT devices may, for example, be in the form of automated equipment that may operate without requiring human supervision or interaction.

[0006] In the current 5G architecture, the base station structure may be split into two or more parts. In some RAN implementations there are two parts, known as the Central Unit (CU or gNB-CU) - sometimes referred to as a 'control unit' - and the Distributed Unit (DU or gNB-DU), connected by an F1 interface. This enables the use of a 'split' architecture in which the typically 'higher' CU layers (for example, but not necessarily or exclusively, Packet Data Convergence Protocol (PDCP) and Radio Resource Control (RRC) layers) and the, 'lower' DU layers (for example, but not necessarily or exclusively, Radio Link Control (RLC), Media (sometimes referred to as 'Medium') Access Control (MAC), and Physical (PHY) layers) are separated between a particular CU, and one or more Dus that are connected to and controlled by that CU via the F1 interface. Thus, for example, the higher layer CU functionality for a number of base stations may be implemented centrally (for example, by a single processing unit, or in a cloud-based or virtualised system), whilst retaining the lower layer DU functionality locally separately for each base station.

[0007] In 5G, core network entities comprise logical nodes (or 'functions') including control plane functions (CPFs) and one or more user plane functions (UPFs). The CPFs include, amongst other things, one or more Access and Mobility Management Functions (AMFs), a session management function (SMF), and one or more location management functions (LMFs). The AMF generally corresponds to the MME in 4G and performs many of the functions performed by the MME. Each UPF combines functionality of both the Serving Gateway (S-GW) and Packet Data Network Gateway (P-GW) - specifically user plane functionality of the S-GW (SGW-U) and user plane functionality of the P-GW (PGW-U). The SMF provides session management functionality (that formed part of MME functionality in 4G). The SMF also combines the some of the functionality provided by the S-GW and P-GW - specifically control plane functionality of the S-GW (SGW-C) and control plane functionality of the P-GW (PGW-C). The SMF also allocates IP addresses to each UE.

[0008] When a UE wishes to access a cell (and / or a beam in the case of 5G) it may attempt to access that cell and / or beam using a random access (RACH) procedure that historically involved four distinct steps. More recently, a simplified access procedure has been developed by which a UE may attempt to access that cell and / or beam using a two-step RACH procedure. Both the four-step and two-step RACH procedures are well known to those skilled in the art.

[0009] In summary, the four-step procedure typically involves the UE selecting random access resources (including, for example, a preamble) that it uses to initiate the RACH procedure. The UE sends the selected preamble in a first message ('Msg1') to a base station over a physical random access channel (PRACH). In response, the base station responds with a random access response (RAR) (or 'Msg2'). The RAR indicates reception of the preamble and includes, amongst other things, an uplink grant field indicating resources to be used in the uplink for a physical uplink shared channel (PUSCH). The UE 3 then sends a third message ('Msg3') to the network over a physical uplink shared channel (PUSCH) based on the information in the RAR. The specific message sent by the UE in this step, and the content of the message, depends on the context in which the random access procedure is being used. For initial RRC connection setup, for example, Msg3 typically comprises an RRC Setup request or similar message carrying a temporary randomly generated UE identifier. The network responds with a fourth message ('Msg4') which carries the randomly generated UE identifier received in Msg3 for contention purposes to resolve any collisions between different UEs using the same preamble sequence. When successful, Msg4 also transfers the UE to a connected state.

[0010] As those skilled in the art will appreciate, while a contention based random access (CBRA) procedure is described, a non-contention based (or 'contention free') procedure may also be used, e.g., in which a dedicated preamble is assigned by the base station to the UE.

[0011] The two-step procedure is similar in terms of the information transferred but involves one UE to base station message ('MsgA') and one base station to UE message ('MsgB'). MsgA, in effect, combines Msg1 and Msg 3 of the four-step procedure, and MsgB, in effect, combines Msg2 and Msg4 of the four-step procedure.

[0012] It will be appreciated that random access procedures such as those mentioned above may also be used in other contexts including, for example, handover, connection reestablishment, requesting UL scheduling where no dedicated resource for a scheduling-request has been configured for the UE, etc.

[0013] Recently, IoT has attracted much attention in the wireless communication world, and as IoT develops and grows, more 'things' are expected to be interconnected to improve productivity efficiency and increase the comforts of life. In this vein efforts have been made to try to reduce the size, complexity, and power consumption of IoT devices to enable the deployment of tens or even hundreds of billions of IoT devices for various applications. Typically, such IoT devices are powered by batteries that need to be replaced or recharged manually. Thus, as the number of IoT devices deployed grows apace, there is an increasingly negative impact from such devices as the need to replace them leads to increasingly high maintenance costs, serious environmental issues, and even safety hazards for some use cases, for example, for the use of wireless sensors in electrical power, and petroleum industries.

[0014] 'Ambient' IoT (A-IoT) attempts to address some of the above issues and relies on ultra-low complexity devices with ultra-low power.

[0015] A-IoT devices (which may also be referred to simply as IoT devices for simplicity) make use of 'backscatter' or 'reflected' communication to communicate with an A-IoT device reader which may be a cellular RAN node (base station), or other device connected to a cellular communication network. Specifically, A-IoT devices transmit data by reflecting or backscattering radio frequency (RF) signals from the A-IoT device reader without necessarily having to actively generate their own RF signals. Instead A-IoT devices effectively modulate their impedance or reflectivity in response to an incoming RF signal (known as an 'unmodulated carrier' or 'unmodulated carrier signal'), which causes the signal to be reflected to a receiver. The backscattered signals (also referred to as 'reflected' signals) carry information, encoded by the modulation, of the impedance or reflectivity of the A-IoT device.

[0016] Such backscattered signals are typically transmitted on the same frequency as the unmodulated carrier signal from which it originated, but alternatively, the backscattered signals may undergo additional processing such that the backscattered signals have an offset from the frequency of the unmodulated carrier signal.

[0017] It can be seen that A-IoT devices and associated A-IoT device readers have much in common with radio frequency identification (RFID) tags and associated RFID readers. However, A-IoT devices need to be able to operate successfully in a conventional, orthogonal frequency-division multiplexing (OFDM) based, cellular communication system, and to co-exist with more complex conventional UEs (such as smart phones, conventional IoT devices, and the like). Accordingly, compared to conventional RFID devices, A-IoT devices and associated A-IoT device readers are typically subject to additional constraints and need to be able to support additional functionality.

[0018] A-IoT devices may be categorised as follows: - Type 1 devices: A-IoT devices that have means of energy storage but no independent signal generation or downlink (DL) / uplink (UL) amplification capabilities. Such devices rely solely on backscatter communication to communicate in the uplink with other devices. Type 1 devices typically have an initial sampling frequency offset (SFO) up to 10Xppm (where the value of X is still to be agreed but may, for example, be 4 or 5). - Type 2a devices: A-IoT devices that have means of energy storage, and no independent signal generation capabilities, but that do have both DL and UL amplification capabilities. Such devices similarly rely on backscatter communication in the uplink to communicate with other devices. For example, the device can use stored energy to amplify signals backscattered on a carrier wave provided externally. Type 2a devices similarly have a typical initial SFO up to 10Xppm (where the value of X is still to be agreed but may, for example, be 4 or 5). - Type 2b devices: A-IoT devices that have means of energy storage and independent signal generation, i.e., the device has active radio frequency (RF) components that can generate signals for transmission. Hence, UL transmissions may be generated internally by the device, or may be backscattered on a carrier wave provided externally. Type 2b devices also have both DL and UL amplification capabilities. For example, the device can use its stored energy to amplify signals backscattered on the carrier wave provided externally. Type 2b devices similarly have a typical initial SFO up to 10Xppm (where the value of X is still to be agreed but may, for example, be 4 or 5).

[0019] It will be appreciated that type 1, 2a, and 2b, are only examples of possible ambient IoT device categories and that other categories and / or types of ambient IoT devices are possible. For example, the term 'type A' device is also sometimes used to refer to an ambient IoT device that has no means of energy storage and no independent signal generation / amplification capabilities. Such devices also rely on backscatter communication to communicate with other devices.

[0020] Typically, type 1, 2a, and 2b devices each have their own set of power consumption targets, complexity targets, latency targets, data rate targets, and the like.

[0021] For example, the power consumption target for type 1 devices during transmitting / receiving is typically set to less than or equal to 1 microwatts (μW), while for both type 2a and 2b devices the power consumption target during transmitting / receiving is typically set to less than or equal to a few hundred microwatts (μW).

[0022] It will be appreciated that the requirement for the power consumption target to be less than or equal to a 'few hundred μW' mentioned here means that a specific value does not need to be set. It is, therefore, open to discussion to ascertain whether a given design has a corresponding power consumption that satisfies this requirement.

[0023] It is envisaged that a coverage design target for A-IoT devices will have a maximum distance of between 10m and 50m when the device is indoors.

[0024] Typically, where such ambient IoT devices are implemented in a communication network / system (also referred to as an ambient IoT network) a maximum connection density target may also be set to ensure optimal performance of the network. Typically, such maximum connection density is set at 150 devices per 100 m2for indoor scenarios, and 20 devices per 100 m2for outdoor scenarios.

[0025] Ambient IoT networks may be configured to have any one of several possible connectivity topologies and may be deployed in several different ways. These topologies include: - Topology 1 in which an ambient IoT device reader (in this example a base station or RAN node) and ambient IoT device communicate with one another directly (including the possibility that the base station that transmits to the ambient IoT device is different to the base station that receives from the ambient IoT device). This topology may, therefore, need to support full duplex operation at the base station to enable backscatter communication. This can be a significant challenge if an incoming RF signal (known as an 'unmodulated carrier' or 'unmodulated carrier signal') and reflected (or backscattered) signal are within the same RF band. - Topology 2 in which a base station (or RAN node) and ambient IoT device communicate with one another via an ambient IoT device reader in the form of an intermediate / assisting node (which may be a relay, an integrated access and backhaul (IAB) node, another UE, a repeater and / or the like, which is capable of ambient IoT operation). The intermediate node transfers ambient IoT data and / or signalling between base station and the ambient IoT device. Like Topology 1, this topology may require support of full duplex operation at the intermediate node and hence faces similar associated challenges. - Topology 3 in which the ambient IoT device: receives data / signalling from the base station (or RAN node) directly but transmits data / signalling to the base station indirectly via an assisting node; or transmits data / signalling to the base station (or RAN node) directly but receives data / signalling from the base station indirectly via an assisting node. Accordingly, in this example some IoT device reader functionality is provided by the base station and some IoT device reader functionality is provided by the assisting node. The assisting node may be a relay, an IAB node, another UE, a repeater and / or the like, which is capable of ambient IoT operation. This topology has the benefit that it does not require the base station, or the assisting node, to have full duplex operation. However, the node receiving the reflected signal needs to be able to differentiate between an unmodulated carrier signal and a reflected signal from an ambient IoT device.

[0026] For Topologies 1 and 2, there may be: none of RRC states typical to conventional UEs (e.g., IDLE, CONNECTED, SUSPENDED and / or the like); none of the mobility procedures typical to conventional UEs (e.g., at least no cell selection / re-selection functionality); and / or none of the automatic repeat request (ARQ) and / or hybrid-ARQ (HARQ) typical to conventional UEs.

[0027] Typically in ambient IoT-based systems the user experienced data rate target is between 0.1 kbps and 5 kbps (with 1 kbps being a typical rate), and the design target of the maximum message size is approximately 1000 bits over both the 'device-to-reader' ('D2R') link, and the 'reader-to-device' ('R2D') link, which is in turn based on the maximum possible application layer packet size. Thus assuming a 1 kbps data rate, it takes 1s to transmit 1000 bits over the D2R and R2D links.

[0028] Currently it is envisaged that, for A-IoT, fewer physical channels will be supported, and UL and DL physical layer (layer-1 (L1)) communication will be simplified significantly. For example, there may be a single physical R2D channel (PRDCH) for R2D communication and a single physical D2R channel (PDRCH) for D2R communication. For R2D, the PRDCH will typically carry any higher-layer payload, and any L1 R2D control information (if defined). For D2R, the PDRCH will typically carry any higher-layer payload, and any L1 D2R control information (if defined). The PDRCH may also carry, for example, a response transmitted from the A-IoT device to a reader during a contention-based access procedure. The current view is that R2D transmission will typically comprise an R2D preamble to indicate a start time of the following PRDCH and possibly and chip length information. This R2D preamble is followed immediately by the PRDCH transmission (carrying any R2D traffic data and / or any control information). An R2D postamble is transmitted immediately after the PRDCH transmission to indicate an end of the PRDCH transmission. Similarly, for D2R transmissions, it is envisaged that a D2R preamble will be transmitted at the beginning of each D2R transmission, immediately before the PDRCH transmission, to indicate a start time of the PDRCH transmission. A D2R postamble may also be transmitted following the PDRCH transmission to indicate the end of the PDRCH transmission (and possibly provide a final timing correction to the A-IoT device reader). In the context of D2R communication, however, a D2R midamble may be inserted into (sent during) the PDRCH transmission, for facilitating chip-level timing tracking and channel / interference estimation (e.g., depending on the length of that PDRCH transmission).

[0029] Thus, as the R2D preamble is used to indicate the start of each R2D transmission, the R2D postamble implicitly indicates the TBS of the PDRCH transmission by indicating the end of each R2D transmission. Accordingly, there is no need to restrict the timing of the R2D transmission to align with a conventional OFDM slot (e.g., an NR slot in a 5G system). Moreover, given the potential for a large number of small packets to be transmitted via A-IoT communications, flexible and efficient scheduling can be facilitated by not imposing a constraint that the boundary of the R2D transmission should align with that of the OFDM (e.g. NR) slots. Nevertheless, since the R2D transmission waveform is an OFDM-based waveform, the start of a R2D transmission may be aligned with the boundary of an OFDM (e.g., NR) symbol (including any cyclic prefix) when the R2D transmission co-exists with such transmissions) for in-band and guard-band operations.

[0030] Generally, for A-IoT communication, it is envisaged that multiple A-IoT logical channels for communication of upper layer data need not be supported. It is yet to be determined whether the concept of A-IoT logical channels is used (e.g., depending on final modelling issues). It is also envisaged that access stratum (AS) layer (above the PHY layer) RLC-like retransmission / repetition will not be supported for A-IoT. Nevertheless, this does not preclude the reader and device resending the payload again as a new transmission from the perspective of the MAC layer. It is yet to be determined how segmentation is to be handled (if needed).

[0031] Due to the simplicity of A-IoT technology, new random access procedures are being developed for allowing communication between an A-IoT device and the A-IoT device reader. These A-IoT access procedures are typically based on a slotted Additive Links On-line Hawaii Area (slotted-ALOHA) based algorithm / protocol that is widely used for communication between radio frequency identification (RFID) tags and their associated RFID reader. Slotted-ALOHA is a variation of the ALOHA protocol, which will be familiar to those skilled in the art. In slotted-ALOHA, a communication channel is effectively divided into small, fixed-length, time slots. Devices are only able to transmit data at particular times (e.g., during specific transmission occasions).

[0032] For random access in the context of RFID technology, as RFID tags are passive devices, the RFID reader needs to initiate any communication access from the RFID tags to the RFID reader. Specifically, communication between the RFID reader and the RFID tags is performed as part of a procedure called an inventory round. Initially, before the inventory process commences, the RFID reader typically transmits a 'Select' command to all RFID tags in the coverage area of the RFID reader, to select a particular group of the RFID tags that are allowed to respond to the RFID reader in the subsequent procedure. The Select command includes information that allows the RFID tags to identify if they are allowed to respond - for example, a device identifier (optionally with a mask) such as an electronic product code (EPC) (or part of it), and / or part of the information in the RFID tag's memory. Any RFID tag that matches the information in the Select command may respond. The RFID reader then sends a 'Query' command to initiate a random access like identification process and sets the parameters to be used for subsequent RFID tag to RFID reader communication.

[0033] Selected RFID tags (i.e., those that match the parameters in the Select command) then randomly determine a 'random access' slot (or 'reply slot') to reply in based on information in the 'Query' command. This reply slot may be the first slot (slot #0) or a subsequent slot. Selected RFID tags that do not respond immediately to the Query command in the first slot (slot #0) move to an Arbitrate state and wait to receive either a QueryAdjust command (to adjust one or more parameters provided in the original Query command and trigger the affected RFID tags to determine a new slot to reply in) or a QueryRep command (to indicate a transition to the next slot and hence the affected RFID tags to modify (decrease) an associated slot counter indicating a number of slots until the determined reply slot).

[0034] When a given selected RFID tag responds in a corresponding reply slot, that RFID tag does so by sending a 16-bit random number (RN16) to the RFID reader (the sending of this RN16 parameter is analogous to the transmission of Msg1 in conventional cellular random access procedures). This 16-bit random number may be used, for example, for the purposes of contention resolution in the event that a plurality of selected RFID tags select the same slot for response, and hence respond to the Query command simultaneously.

[0035] Assuming that a single RFID tag has responded to the RFID reader in a given slot, the RFID reader confirms reception of the with an acknowledgement (ACK command) containing the same RN16 value (the sending of this acknowledgement is analogous to the transmission of the RAR / Msg2 in conventional cellular random access procedures). On receipt of the acknowledgement with the same RN16 value, the RFID tag that responded enters an acknowledged state and responds to the RFID reader with an EPC (a unique identifier of the RFID tag), a cyclic-redundancy check (CRC) and a protocol-control (PC) (the sending of this information is analogous to the transmission of Msg3 in conventional cellular random access procedures).

[0036] The RFID reader then sends a QueryAdjust or QueryRep command, triggering the RFID tag that has just communicated with it to return to a Ready state, and triggering the remaining selected RFID tags in the current identification process to decrease their slot counters. If no RFID tags respond in a given slot RFID reader may send another QueryRep command to trigger the remaining selected RFID tags in the current identification process to decrease their slot counters again.

[0037] For random access in the context of A-IoT devices and A-IoT device readers it is envisaged that when a response is expected from multiple devices (e.g., for the purposes of identifying multiple devices in the vicinity of the A-IoT device reader) a contention-based random access procedure may be used. This contention-based random access procedure may, for example, be similar to a conventional four-step RACH procedure or to a conventional two-step RACH procedure, and may also have some similarities with the RFID random access procedure.

[0038] NPL 1: 'NGMN 5G White Paper' V1.0 by the Next Generation Mobile Networks (NGMN), available from https: / / www.ngmn.org / 5g-white-paper.html.

[0039] In an A-IoT 'four-step' random access procedure, like the RFID random access procedure, random access is triggered by the A-IoT device reader using an appropriate reader-to-device (R2D) trigger message ('A-IoT Msg0') in a manner that is analogous to the Query command of the RFID random access procedure. The A-IoT device reader includes, in this trigger message, the information (appropriate parameters) that the A-IoT device needs to respond to the random access trigger. It is possible that this trigger message may trigger initial access by a single device, a group of devices, or all devices in a cell / coverage area.

[0040] When triggered by the R2D trigger message (A-IoT Msg0), the A-IoT device may send an initial device-to-reader (D2R) message ('A-IoT Msg1') carrying a corresponding identifier (e.g., a random ID generated by A-IoT device), and possibly other information, to the A-IoT device reader. The A-IoT device reader echoes the identifier received in the initial D2R message (A-IoT Msg1) back to the A-IoT device in an R2D response message ('A-IoT Msg2') that may include additional useful information where appropriate. The A-IoT device may then send a further D2R message ('A-IoT Msg3') including the A-IoT device's device identifier and / or any other higher layer data (depending on a higher layer request). It will be appreciated that the A-IoT device may consider contention resolution to be successful, if the received response message (A-IoT Msg2) includes the same random identifier that was sent by that A-IoT device in the initial D2R message (A-IoT Msg1). Hence the size of the random identifier needs to be sufficient for effective contention resolution purposes. A further R2D transmission ('A-IoT Msg4') may then be sent by the A-IoT device reader to the A-IoT device after the further D2R message (A-IoT Msg3) but does not always need to be sent. The further R2D transmission (A-IoT Msg4) may, for example, be sent to handle a transmission failure (e.g., a failure of A-IoT Msg3 due to any of a number of different reasons). It will be appreciated that the 'A-IoT Msg' terms (e.g., 'A-IoT Msg4') may or may not be used in practice.

[0041] Similarly, in an A-IoT 'two-step' random access procedure, like the RFID random access procedure, random access is triggered by the A-IoT device reader using an appropriate reader-to-device (R2D) trigger message ('A-IoT Msg0') in a manner that is analogous to the Query command of the RFID random access procedure.

[0042] In the two-step scenario, however, when triggered by the R2D trigger message (A-IoT Msg0), the A-IoT device may send an initial device-to-reader (D2R) message ('A-IoT Msg1') carrying a corresponding device identifier (e.g., a random ID generated by A-IoT device or some other identifier), and / or any other higher layer data (depending on a higher layer request), to the A-IoT device reader. This initial D2R message may also include other appropriate information. The A-IoT device reader may echo some or all of the information received in the initial D2R message (A-IoT Msg1) back to the A-IoT device in a R2D response message ('A-IoT Msg2') that may include additional useful information where appropriate.

[0043] Whilst the overall contention based A-IoT two-step and four-step random access procedures have been developed, however, there is still a need for further enhancement to those procedures. For example, there is still a need to further develop A-IoT random access to take account of scenarios in which at least some A-IoT devices are operated in a duty-cycle manner - e.g., to take account of the possibility of A-IoT device unavailability due to charging by energy harvesting during an OFF / SLEEP period / duration.

[0044] In more detail, a conventional RFID device may be activated (woken up) whenever it receives an RF signal with sufficient energy (e.g., a power exceeding a sensitivity of the RFID device or a given activation threshold). The RFID device may then remain in an ON state (or 'mode') to receive and / or transmit using energy harvested from the incident RF signal.

[0045] Contrastingly, as mentioned above, A-IoT devices will typically have energy storage and can therefore be charged based on RF energy harvesting. Accordingly, A-IoT devices can wake up even when RF incident power is not particularly high. Whilst stored energy may (at least for type 1 A-IoT devices) be used to reduce the threshold of RF incident power required to wake up this way may not be appropriate (especially in in-band / guard-band deployment scenarios) because such A-IoT devices may be triggered to wake up by RF incident power higher than the lowered threshold arising from spurious signals (e.g. RF interference). Such unnecessary waking up wastes energy and could cause any stored energy to be exhausted most of the time meaning that the A-IoT device will not be able to rely on stored energy to wake up.

[0046] To alleviate such issues it is envisaged that A-IoT devices may employ a duty cycle mechanism / duty cycle monitoring (DCM) in which the A-IoT device recurringly (at periodic or aperiodic intervals) operates in an 'ON' (or active) state for a (pre)configured (or possibly dynamically indicated) time period / duration (an 'on' or 'active' period) to monitor for R2D transmissions (e.g., random access (RA) triggers) and / or perform transmission for D2R communication and / or reception for R2D communication, before automatically entering (or being triggered to enter) a 'SLEEP' (or 'OFF' or 'inactive') state for a (potentially different) time period / duration. During the SLEEP (or 'OFF' or 'inactive') state, the device may harvest (and store) RF energy from RF signals incident at the A-IoT device (regardless of how strong those RF signals are).

[0047] Additionally, during a SLEEP state, while the device does not support transmissions, the device may support maintaining the contents / data / information stored in a memory of the device during the 'ON' state (where such a memory is provided). Additionally (or alternatively), during the SLEEP state, the device may support the maintenance of one or more timers (or clocks as implemented in hardware); for example, the device may trigger a timer upon entering a SLEEP state, and may switch to an ON state (or an 'OFF' state) upon expiration of those one or more timers.

[0048] The nature of the DCM employed (e.g., the number and functionality of the different DCM states / modes) may be different for different A-IoT devices / device types. For example, type 1 A-IoT devices may be configured to use two discrete states / modes (e.g., 'ON' and 'OFF') whereas type 2 (2a and / or 2b) A-IoT devices may be configured to use three discrete states / modes (e.g., 'ON', 'OFF', and 'SLEEP'). Nevertheless, while it may be preferable in certain situations for type 1 A-IoT devices to be configured to use two discrete states / modes (e.g., 'ON' and 'OFF') and for type 2 (2a and / or 2b) A-IoT devices to be configured to use three discrete states / modes (e.g., 'ON', 'OFF', and 'SLEEP'), it will be appreciated that both type 1 and type 2 A-IoT devices may be configured to use three discrete states / modes (e.g., 'ON', 'OFF', and 'SLEEP') - for example, where both type 1 and type 2 A-IoT devices are deployed with both a memory and one or more timers (e.g., clocks implemented in hardware).

[0049] In an 'ON' state the A-IoT device may, for example, be configured to support (at least) D2R transmission and R2D reception for the purposes of communication with the A-IoT device reader (e.g., in addition to energy harvesting). On the other hand, whilst in an 'OFF' state, the A-IoT device may be configured: not to support (at least) D2R transmission and R2D reception for the purposes of communication; but to support (at least) energy harvesting from incident A-IoT signals. Contrastingly, while in a 'SLEEP' state, the A-IoT device may be configured: to support (at least) retention of (at least some) memory content from a previous ON state and maintenance of one or more timers (possibly in addition to energy harvesting); but not to support (at least) D2R transmission. Moreover, for A-IoT devices that support a 'SLEEP' state it is envisaged that no additional physical layer signals / channels will be introduced to support such a 'SLEEP' state. It will be appreciated that the precise definition of each state may vary. For example, even in an OFF state the A-IoT device could, potentially, be configured to retain some memory and keep a clock running for maintenance of one or more timers.

[0050] A given duty cycle employed by an A-IoT device implementing DCM may thus involve periodic / aperiodic transitions from an ON state to a SLEEP state and then back to the ON state with some memory being retained and possibly a clock kept running (this may be referred to as 'light-sleep' DCM); or periodic / aperiodic transitions from an ON state to an OFF state (in which no memory / timer is maintained) and then back to the ON state (this may be referred to as 'deep-sleep' DCM). It will be appreciated that in each of these DCM types the (net) rate of energy harvesting may be different.

[0051] It will be appreciated that such periodic / aperiodic transitions from an ON state to a SLEEP state and then back to the ON state, and such periodic / aperiodic transitions to and from an OFF state may be triggered based on the occurrence of a specific event. For example, an A-IoT device may be triggered to transition from an ON state to a SLEEP state based on scheduling information indicating when the next ON state operations are scheduled; and / or based on an indication that the A-IoT device has insufficient energy to perform ON state operations; and / or after the A-IoT device receiving a paging message, or the like, indicating that a A-IoT device reader does not intend to communicate with it for a period of time, and the like.

[0052] In another example, an A-IoT device may be triggered to transition from an ON / SLEEP state to an OFF state based on the A-IoT device having insufficient energy to retain its memory content.

[0053] In yet another example, an A-IoT device may be triggered to transition from a SLEEP state to an ON state once the A-IoT device is sufficiently charged to support ON state operations; and / or based on scheduling information indicating when the next ON state operations are scheduled; and / or based on receiving a wake-up signal (WUS), or the like.

[0054] Nevertheless, while transitions may be triggered based on the occurrence of (pre)configured triggering events such as those outlined above, it will be appreciated that there may be situations where it would be preferable for a given A-IoT device to enter an OFF state even though that A-IoT device would otherwise enter a SLEEP state (and has sufficient energy to support operations associated with its SLEEP state). For example, it may be preferable for the A-IoT device to transition to an OFF state to achieve greater energy savings in the A-IoT system, and to conserve more of the energy stored at the A-IoT device, compared to when that A-IoT device is in a SLEEP state.

[0055] The disclosure aims to describe one or more apparatus and / or one or more associated mechanisms / procedures that at least partially addresses or contributes to meeting one or more of the above needs and / or addressing one or more of the above issues.

[0056] The disclosure has a method performed by a reader device, the method comprising transmitting, to a mobile device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled.

[0057] The disclosure has a method performed by a mobile device, the method comprising receiving, from a reader device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled; and enabling or disabling the sleep state of the mobile device based on the information.

[0058] The disclosure has a reader device comprising means for transmitting, to a mobile device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled.

[0059] The disclosure has a mobile device comprising means for receiving, from a reader device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled; and means for enabling or disabling the sleep state of the mobile device based on the information.

[0060] The various functional means described below that are part of the UE / A-IoT device may be provided by a memory and one or more processors that execute instructions stored in the memory. Similarly, the various functional means described below that are part of the access network node / A-IoT device reader may be provided by a memory and one or more processors that execute instructions stored in the memory.

[0061] Various example described below may be implemented by means of a computer program product comprising computer implementable instructions for causing a programmable computer to carry out any of the methods described below. The computer implementable instructions may be provided as a signal or on a tangible computer readable medium.

[0062] Examples of apparatus and methods will now be described, by way of example, with reference to the accompanying drawings in which:

[0063] Fig. 1 illustrates schematically a mobile (cellular or wireless) communication system to which example embodiments of the disclosure may be applied;Fig. 2A illustrates schematically a first possible arrangement of a first connectivity topology (topology 1) that may be used in the communication system of Fig. 1;Fig. 2B illustrates schematically another possible arrangement of a first connectivity topology (topology 1) that may be used in the communication system of Fig. 1;Fig. 3A illustrates schematically a first possible arrangement second connectivity topology (topology 2) that may be used in the communication system of Fig. 1;Fig. 3B illustrates schematically another possible arrangement second connectivity topology (topology 2) that may be used in the communication system of Fig. 1;Fig. 4A illustrates schematically a first possible arrangement of a third connectivity topology (topology 3) that may be used in the communication system of Fig. 1;Fig. 4B illustrates schematically another possible arrangement of the third connectivity topology (topology 3) of Fig. 4A;Fig. 5A illustrates a possible timing structure for an ON-SLEEP transition for an A-IoT device implementing DCM that may be implemented in the communication system 1;Fig. 5B illustrates another possible timing structure for an ON-SLEEP transition for an A-IoT device implementing DCM that may be implemented in the communication system 1;Fig. 5C illustrates a possible timing structure for a SLEEP-ON transition for an A-IoT device implementing DCM that may be implemented in the communication system 1;Fig. 5D illustrates another possible timing structure for a SLEEP-ON transition for an A-IoT device implementing DCM that may be implemented in the communication system 1;Fig. 6 illustrates yet another possible timing structure for another SLEEP-ON transition for a plurality of A-IoT devices implementing DCM that may be implemented in the communication system 1;Fig. 7 illustrates a simplified sequence diagram of a procedure for selectively enabling / disabling a SLEEP state of an A-IoT device that may be implemented in the communication system of Fig. 1;Fig. 8A illustrates an example timing structure for an enhanced ON-OFF transition procedure that may be performed by an A-IoT device implementing DCM in the communication system 1;Fig. 8B illustrates an example timing structure for an enhanced ON-SLEEP transition procedure that may be performed by an A-IoT device implementing DCM in the communication system 1;Fig. 9 illustrates an example timing structure for an enhanced ON-SLEEP / SLEEP-ON transition procedure that may be performed by an A-IoT device implementing DCM in the communication system 1;Fig. 10 illustrates an example timing structure for another enhanced ON-SLEEP / SLEEP-ON transition procedure that may be performed by an A-IoT device implementing DCM in the communication system 1;Fig. 11 illustrates a simplified sequence diagram of a procedure for indicating a paging periodicity offset to an A-IoT device for use in its transitions from a SLEEP state to an ON state;Fig. 12 is a simplified block schematic illustrating the main components of a user equipment that may be used in the communication system of Fig. 1;Fig. 13 is a simplified block schematic illustrating the main components of an ambient IoT device that may be used in the communication system of Fig. 1;Fig. 14 is a simplified block schematic illustrating the main components of a RAN node that may be used in the communication system of Fig. 1; andFig. 15 is a simplified block schematic illustrating the main components of an intermediate or assisting node that may be used in the communication system of Fig. 1.

[0064] <Overview> 　　An exemplary telecommunication system will now be described in general terms, by way of example only, with reference to Figs. 2 to 5.

[0065] Fig. 2A and Fig. 2B schematically illustrates a mobile ('cellular' or 'wireless') communication system (e.g., communication system 1) to which examples of the present disclosure are applicable.

[0066] In the communication system 1, user equipments (UEs) 3 (3-1, 3-2, 3-3) (e.g., mobile telephones and / or other mobile devices including (ambient) IoT devices) can communicate with each other via a corresponding radio access network (RAN) node 5-1 that operates according to one or more compatible radio access technologies (RATs). In the illustrated example, the RAN node 5-1 comprises a base station operating one or more associated cells 9. Communication via the RAN node 5-1 is typically routed through a core network 7 (e.g., a 5G core network or evolved packet core (EPC) network). As those skilled in the art will appreciate however, a base station 5-1 or 'gNB' 5-1 is an example of a RAN node 5-1 only and that the RAN node 5-1 may be any appropriate RAN node 5-1 (e.g., where appropriate the RAN node 5-1 may be a RAN node 5-1 that operates using a different RAT than NR / 5G).

[0067] As those skilled in the art will appreciate, whilst three UEs 3, and one RAN node 5-1 are shown in Fig. 2A and Fig. 2B for illustration purposes, the system, when implemented, will typically include other RAN nodes 5-1 and UEs 3.

[0068] In the illustrated example, the UEs 3 include at least one 'ambient' IoT device 3-1 (A-IoT device 3-1) that is capable of performing backscatter communication and a number of other, non-ambient IoT, UEs 3-2, 3-3 (such as smartphones or the like) that communicate in a conventional manner.

[0069] The A-IoT device 3-1 may, for example, be a Type 1, Type 2a, or Type 2b device as described in the introduction. As described in more detail later, depending on the connectivity topology employed, the A-IoT device 3-1 may be configured for uplink (backscatter) communication and / or downlink communication directly with the RAN node 5-1 and / or may be configured for uplink (backscatter) communication and / or downlink communication indirectly via communication (e.g., 'sidelink' or similar communication) with intermediate, or assisting, node 5-2. It will be appreciated that the intermediate, or assisting, node 5-2 may, in effect, be another node of the RAN, a separate RAN or other type of communication node, or another UE 3 that communicates with the A-IoT device 3-1 via an appropriate device-to-device interface (e.g., D2D, sidelink, PC5 or the like). The intermediate, or assisting, node 5-2 may, for example, be a relay node (e.g., a dedicated relay or UE-relay), an integrated access and backhaul (IAB) node, a repeater and / or the like, which is capable of ambient IoT operation including receiving backscatter / reflected signals from, and / or transmitting unmodulated carrier signals to, the A-IoT device 3-1.

[0070] The RAN node 5-1 controls one or more associated cells 9 either directly, or indirectly via one or more other nodes (such as home base stations, relays, remote radio heads, distributed units, and / or the like). It will be appreciated that the RAN node 5-1 may be configured to support 4G, 5G, 6G and / or later generation, and / or any other 3GPP or non-3GPP communication protocols.

[0071] The RAN node 5-1 may be a distributed base station comprising at least one distributed unit (DU) (e.g., a gNB-DU or the like), and a central unit (CU) (e.g., a gNB-CU or the like). In such a distributed base station the CU employs a separated control plane and user plane and so is, itself, split between a control plane function (CU-CP) and a user plane function (CU-UP) which respectively communicate, with the DU via an appropriate interface (e.g. F1-C logical interface) and an appropriate interface (e.g. F1-U logical interface) (together forming an F1 interface (or 'reference point')), and with one another via an appropriate interface (e.g. E1 logical interface). It will be appreciated that while the DU may include the physical and virtual elements required to provide the functionality of the lower parts of the PHY layer and hence communicate with the UEs 3 over the air interface, the base station may alternatively (or additionally) include one or more separate radio units (RUs) (e.g., providing this functionality of the lower parts of the PHY layer). It will, nevertheless, be appreciated that the RAN node 5-1 may be a base station may of a non-distributed form, for example as an integrated base station.

[0072] The UEs 3 (and possibly the intermediate or assisting node 5-2 if present) are configured for communication with the RAN node 5-1 via an appropriate air interface (for example a so-called 'Uu' interface and / or the like). It will be appreciated that the A-IoT device 3-1 may, alternatively or additionally, be configured for indirect communication with the RAN node 5-1 via an (air) interface with the intermediate or assisting node 5-2 (if present) and an (air) interface between the intermediate or assisting node 5-2 and the RAN node 5-1. Neighbouring RAN nodes 5-1 may be connected to each other via an appropriate base station to base station interface (such as the so-called 'X2' interface, 'Xn' interface and / or the like - not shown in Fig. 2A and Fig. 2B).

[0073] The core network 7 includes a number of logical nodes (or 'functions') for supporting communication in the communication system 1. In this example, the core network 7 comprises control plane functions (CPFs) 10 and one or more network node entities for the communication of user data (e.g. user plane functions (UPFs) 11). The CPFs 10 include one or more network node entities for the communication of control signalling (e.g. Access and Mobility Management Functions (AMFs) 10-1), one or more network node entities for session management (e.g. Session Management Functions (SMFs) 10-2) and a number of other functions 10-n. Additional functions may include, for example: an Authentication Server Function (AUSF) which facilitates security processes; a Unified Data Management (UDM) entity for managing user specific data (e.g., for access authorisation, user registration, and data network profiles); a Policy Control Function (PCF); an Application Function (AF); a Security Anchor Function (SEAF) which is in a serving network and acts as a "middleman" during an authentication process between a UE and its home network; an Authentication credential Repository and Processing Function (ARPF) which maintains the authentication credentials; and / or the like. It will be appreciated that the nodes or functions may have different names in different systems.

[0074] The RAN node 5-1 is connected to the core network nodes via appropriate interfaces (or 'reference points') such as an N2 reference point between the RAN node 5-1 and the AMF 10-1 for the communication of control signalling, and an N3 reference point between the RAN node 5-1 and each UPF 11 for the communication of user data. At least the non-ambient IoT UEs 3-2, 3-3 are each connected to the AMF 10-1 via a non-access stratum (NAS) connection over an appropriate reference point (e.g., N1 reference point (analogous to the S1 reference point in LTE)). It will be appreciated, that N1 communication is routed transparently via the RAN node 5-1.

[0075] One or more UPFs 11 are connected to an external data network 21 (e.g., an IP network such as the internet) via an appropriate reference point (e.g., N6 reference point) for communication of the user data. The AMF 10-1 performs mobility management related functions, maintains the NAS connection with at least each non-ambient IoT UE 3-2, 3-3 and manages UE registration. The AMF 10-1 is also responsible for managing paging.

[0076] The SMF 10-2 is connected to the AMF 10-1 via an appropriate reference point (e.g., N11 reference point). The SMF 10-2 provides session management functionality (that formed part of MME functionality in LTE) and additionally combines some control plane functions (provided by the serving gateway and packet data network gateway in LTE). The SMF 10-2 also allocates IP addresses to at least each non-ambient IoT UE 3-2, 3-3. The SMF 10-2 uses user information provided via the AMF 10-1 to determine what session manager would be best assigned to the user. The SMF 10-2 may be considered effectively to be a gateway from the user plane to the control plane of the network. The SMF 10-2 also allocates IP addresses to at least each non-ambient IoT UE 3-2, 3-3.

[0077] Each RAN node 5-1 is also configured for transmission of, and at least the non-ambient IoT UEs 3-2, 3-3 are configured for the reception of, control information and user data via a number of downlink (DL) physical channels and for transmission of a number of physical signals. The DL physical channels correspond to resource elements (REs) carrying information originated from a higher layer, and the DL physical signals are used in the physical layer and correspond to Res which do not carry information originated from a higher layer.

[0078] The physical channels may include, for example, a physical downlink shared channel (PDSCH), a physical broadcast channel (PBCH), and a physical downlink control channel (PDCCH). The PDSCH carries data sharing the PDSCH's capacity on a time and frequency basis. The PDSCH can carry a variety of items of data including, for example, user data, UE-specific higher layer control messages mapped down from higher channels, system information blocks (SIBs), and paging. The PDCCH carries downlink control information (DCI) for supporting a number of functions including, for example, scheduling the downlink transmissions on the PDSCH and also the uplink data transmissions on a physical uplink shared channel (PUSCH). The PBCH provides at least the non-ambient IoT UEs 3-2, 3-3 with the Master Information Block (MIB). It also, in conjunction with the PDCCH, supports the synchronisation of time and frequency, which aids cell acquisition, selection and re-selection.

[0079] The DL physical signals may include, for example, reference signals (RSs) and synchronisation signals (SSs). A reference signal (sometimes known as a pilot signal) is a signal with a predefined special waveform known to both the UE 3 and the RAN node 5-1. The reference signals may include, for example, cell specific reference signals, UE-specific reference signal (UE-RS), downlink demodulation signals (DMRS), and channel state information reference signal (CSI-RS).

[0080] Similarly, at least the non-ambient IoT UEs 3-2, 3-3 are configured for transmission of, and the RAN node 5-1 is configured for the reception of, control information and user data via a number of uplink (UL) physical channels corresponding to REs carrying information originated from a higher layer, and UL physical signals which are used in the physical layer and correspond to REs which do not carry information originated from a higher layer. The physical channels may include, for example, the PUSCH, a physical uplink control channel (PUCCH), and / or a physical random access channel (PRACH). The UL physical signals may include, for example, demodulation reference signals (DMRS) for a UL control / data signal, and / or sounding reference signals (SRS) used for UL channel measurement.

[0081] Moreover, at least the non-ambient IoT UEs 3-2, 3-3 and the RAN node 5-1 are mutually configured for performing a random access channel (RACH) procedure for those UEs 3-2, 3-3 to access the network. Specifically, on detection and selection of a cell (and / or a beam in the case of 5G) a UE 3 is able to attempt access to that cell and / or beam using an initial radio resource control (RRC) connection setup procedure comprising a random access procedure with the RAN node 5-1.

[0082] Prior to attempting initial access, at least a non-ambient IoT UE 3-2, 3-3 will choose random access resources (including, for example, a preamble) to use to initiate the RACH procedure. The UE 3 sends the selected preamble (e.g., in 'Msg1') to the RAN node 5-1 over a physical random access channel (PRACH) for initiating the process to obtain synchronisation in the uplink (UL). In response, the RAN node 5-1 responds with a random access response (RAR) (or 'Msg2'). The RAR indicates reception of the preamble and includes: a timing-alignment (TA) command for adjusting the transmission timing of the UE 3 based on the timing of the received preamble; an uplink grant field indicating the resources to be used in the uplink for a physical uplink shared channel (PUSCH); a frequency hopping flag to indicate whether the UE is to transmit on the PUSCH with or without frequency hopping; a modulation and coding scheme (MCS) field from which the UE can determine the MCS for the PUSCH transmission; and a transmit power control (TPC) command value for setting the power of the PUSCH transmission. The UE 3 then sends a third message ('Msg3') to the RAN node 5-1 over a physical uplink shared channel (PUSCH) based on the information in the RAR. The specific message sent by the UE 3 in this step, and the content of the message, depends on the context in which the random access procedure is being used. In the example of initial RRC connection setup, however, Msg3 typically comprises an RRC Setup request or similar message carrying a temporary randomly generated UE identifier. The RAN node 5-1 responds with a fourth message ('Msg4') which carries the randomly generated UE identifier received in Msg3 for contention purposes to resolve any collisions between different UEs using the same preamble sequence. When successful, Msg4 also transfers the UE to a connected state.

[0083] At least the non-ambient IoT UEs 3-2, 3-3 and the RAN node 5-1 are also mutually configured for performing a two-step RACH procedure that involves the UE 3-2, 3-3 sending one message ('MsgA') to the RAN node 5-1 and the RAN node 5-1 sending one message ('MsgB') to the UE 3-2, 3-3. MsgA, in effect, combines Msg1 and Msg 3 of the four-step procedure, and MsgB, in effect, combines Msg2 and Msg4 of the four-step procedure.

[0084] While contention-based RACH procedures are described it will be appreciated that a UE 3 and the RAN node 5-1 may also perform a non-contention based (or 'contention free') procedure in which a dedicated preamble is assigned by the RAN node 5-1 to the UE 3. Moreover, a UE 3 and the RAN node 5-1 may perform a two-step RACH procedure.

[0085] Each A-IoT device 3-1 may be completely passive or may be active and configured with at least a subset of the functionality of the non-ambient IoT UEs 3-2, 3-3. It will be appreciated that the specific functionality with which the A-IoT device 3-1 is configured is dependent on the type of A-IoT device as described above. It will, nevertheless, be appreciated that regardless of the non-ambient IoT UE functionality that an A-IoT device may be configured with, each A-IoT device 3-1 is respectively configured with A-IoT specific functionality and each RAN node 5-1 is configured with corresponding functionality for communication with A-IoT devices 3-1.

[0086] For example, each RAN node 5-1 is also configured for transmission of, and the A-IoT devices 3-1 are configured for the reception of, control information and data via a physical R2D channel (PRDCH) for R2D communication that will typically carry any higher-layer payload, and any L1 R2D control information (if defined). Similarly, each RAN node 5-1 is also configured for reception of, and the A-IoT devices 3-1 are configured for the transmission of, control information and data via a physical D2R channel (PDRCH) for D2R communication that will typically carry any higher-layer payload, and any L1 D2R control information (if defined).

[0087] <Connectivity Topologies> 　　The A-IoT device 3-1 may form part of an ambient IoT network having any one of the possible connectivity topologies referred to in the introduction and may be deployed in any of several different ways. Possible connectivity topologies and their deployment will now be described in more detail with reference to Figs. 2 to 4.

[0088] Fig. 2A illustrates schematically a first possible arrangement of a first connectivity topology (topology 1) that may be used in the communication system 1.

[0089] As shown in Fig. 2A, in the first possible arrangement of topology 1 the functionality of an A-IoT device reader is implemented as part of a RAN node 5-1. An A-IoT device 3-1 and the RAN node 5-1 engage in direct communication with one another (i.e., without the presence of an assisting or intermediate node 5-2). Specifically, as shown, the A-IoT device 3-1 directly and bidirectionally communicates with the RAN node 5-1. The communication between the RAN node 5-1 and the A-IoT device 3-1 may, for example, include ambient IoT data and / or other ambient IoT signalling (e.g., control signals or the like). The communication between the RAN node 5-1 and the A-IoT device 3-1 may occur over an appropriate air interface such as the NR Uu air interface, a dedicated interface for ambient IoT, or the like.

[0090] In this example, the RAN node 5-1 is responsible for transmission of an unmodulated carrier signal 20-1 to the A-IoT device 3-1; also known as the 'Carrier Wave' signal (CW). That unmodulated carrier signal 20-1 (or CW) may be transmitted by the RAN node 5-1 to the A-IoT device 3-1 to provide the A-IoT device 3-1 with a signal and / or energy upon which modulated and backscattered / reflected information can be sent. For example, upon receiving a reader-to-device (R2D) signal 20-2 from the RAN node 5-1, the A-IoT device 3-1 may modulate the unmodulated carrier signal 20-1 (or CW) it received based on the R2D signal 20-2 it received and backscatter / reflect that modulated signal as a backscattered device-to-reader (D2R) signal 20-3, to the RAN node 5-1.

[0091] Such transmission of an unmodulated carrier, and receipt of backscattering by the same RAN node (base station) may, for example, be supported by topology 1 where full duplex operation is supported at that RAN node.

[0092] Nevertheless, while Fig. 2A shows the unmodulated carrier signal 20-1 (or CW) and the R2D signal 20-2 as originating from the same RAN node; namely RAN node 5-1, it will be appreciated that topology 1 also allows for the possibility that the RAN node 5-1 (in this case the 'IoT device reader') that communicates with the A-IoT device 3-1 may be a different communication node than a communication node that provides the unmodulated carrier signal 20-1 (or CW).

[0093] For example, as shown in Fig. 2B, which illustrates schematically a second possible arrangement of the first connectivity topology (topology 1) that may be used in the communication system 1, a separate communication node 6 may transmit the unmodulated carrier signal 20-1 (or CW) to the A-IoT device 3-1 to provide the A-IoT device 3-1 with a signal and / or energy based upon which modulated and backscattered / reflected information can be sent. The RAN node 5-1 acting as the A-IoT device reader may then provide the R2D signals 20-2 to the A-IoT device 3-1. Upon receiving an R2D signal 20-2, the A-IoT device 3-1 modulates the unmodulated carrier signal 20-1 (or CW) it received (e.g., based on an R2D signal 20-2 it received) and backscatter / reflect that modulated signal as a backscattered D2R signal 20-3 to the RAN node 5-1.

[0094] Topology 1 may typically be deployed for indoor scenarios, with a type 1, 2a, and / or 2b A-IoT device and the RAN node 5-1 (IoT device reader) being located in an indoor environment. In this scenario the RAN node 5-1 typically supports one or more small cells (e.g., micro-, and pico- cells) used for voice, video, and data transmission, which are designed to provide network coverage to small areas and operate on either licensed frequency division duplex (FDD), licensed time division duplex (TDD), or unlicensed parts of the spectrum.

[0095] Alternatively, topology 1 may be deployed for scenarios where the A-IoT device 3-1 is in an indoor environment but the RAN node 5-1 is located in an outdoor environment. In this case, the RAN node 5-1 may be configured to support one or more small cells (e.g., micro-cells) used for voice, video, and data transmission, which are designed to provide network coverage to small areas and operate on either licensed FDD, licensed TDD, or unlicensed parts of the spectrum. Alternatively, the RAN node 5-1 may support one or more larger cells (e.g., macro- cells) providing radio coverage to a large area, and that operate on either licensed FDD, licensed TDD, or unlicensed parts of the spectrum.

[0096] Topology 1 may also be deployed for outdoor scenarios with one or more A-IoT devices 3-1 and the RAN node 5-1 are located in an outdoor environment. In such scenarios the RAN node 5-1 may support one or more small cells (e.g., micro-cells) used for voice, video, and data transmission, which are designed to provide network coverage to small areas and operate on either licensed FDD, licensed TDD, or unlicensed parts of the spectrum. Alternatively (or additionally), the RAN node 5-1 may support larger cells (e.g., macro- cells) providing radio coverage to a large area, and that operate on either licensed FDD, licensed TDD, or unlicensed parts of the spectrum.

[0097] This topology may, for example, be appropriate for a situation in which a RAN node 5-1 needs to fetch data (e.g., a meter record, a sensor reading, an error code and / or the like) from the A-IoT device 3-1. The RAN node 5-1 will send an unmodulated carrier signal as a 'stimulus' signal to the A-IoT device 3-1 which will automatically respond with the required data encoded in the resulting backscattered / reflected signal.

[0098] Fig. 3A illustrates schematically a first possible arrangement of a second connectivity topology (topology 2) that may be used in the communication system 1.

[0099] As shown in Fig. 3A, in the first possible arrangement of topology 2 the functionality of an IoT device reader is implemented as part of an intermediate node 5-2. Specifically, an A-IoT device 3-1 and a RAN node 5-1 engage in communication with one another via the intermediate node 5-2 (which may also be referred to as an assisting node / A-IoT device reader) to transfer ambient IoT data and / or signalling between the RAN node 5-1 and the A-IoT device 3-1. It will be appreciated that while the intermediate node 5-2 is depicted in Fig. 3A as being a type of base station, the intermediate node 5-2 may in fact be any one of an IAB node, a UE 3, a repeater, or the like, or any other appropriate device, as described above, that can act as an intermediary between a RAN node 5-1 and an A-IoT device 3-1 and that is capable of supporting ambient IoT signalling.

[0100] In this example, the A-IoT device 3-1 communicates bidirectionally with the intermediate node 5-2, which is located between the A-IoT device 3-1 and RAN node 5-1, and which is able to transfer ambient IoT data and / or signalling between the RAN node 5-1 and the A-IoT device 3-1.

[0101] Specifically, the communication between the intermediate node 5-2 and the A-IoT device 3-1 may occur over an appropriate air interface. For example, they may communicate over a Uu, a dedicated interface for A-IoT, or any other appropriate interface (e.g., a sidelink-like interface, ProSe interface, PC5 interface, or the like where the intermediate node 5-2 is a UE).

[0102] In a first (downlink) direction a downlink signal may be transmitted from the RAN node 5-1 to the intermediate node 5-2 as part of communication 20-4 between the RAN node 5-1 and the intermediate node 5-2. The downlink signal, once received by the intermediate node 5-2, may trigger transmission of an unmodulated carrier signal / CW 20-1 to the A-IoT device 3-1 (e.g., on a 'sidelink' or similar interface where the intermediate node 5-2 is a UE 3). The downlink signal may be (or may carry) the unmodulated carrier signal 20-1 that is to be transmitted (e.g. relayed) by the intermediate node 5-2 to the A-IoT device 3-1 or may be a trigger signal for triggering transmission of the unmodulated carrier signal 20-1 to provide the A-IoT device 3-1 with an unmodulated carrier signal 20-1 (or CW) based upon which modulated and backscattered / reflected information can be sent. For example, upon receiving an R2D signal 20-2 from the intermediate node 5-2, the A-IoT device 3-1 may modulate the unmodulated carrier signal 20-1 (or CW) it received (e.g., based on the R2D signal 20-2) and backscatter / reflect that modulated signal as a backscattered D2R signal 20-3, to the intermediate node 5-2.

[0103] That is to say, in a second (uplink) direction the intermediate node 5-2 is responsible for receiving a modulated backscattered (D2R) signal 20-3 from A-IoT device 3-1 (e.g., on a 'sidelink' or similar interface where the intermediate node 5-2 is a UE 3). Specifically, the uplink communication may comprise a modulated backscattered signal 20-3 from the A-IoT device 3-1 to the intermediate node 5-2 that is transmitted (e.g., on a 'sidelink' or similar interface where the intermediate node 5-2 is a UE 3) in using the unmodulated carrier signal 20-1 from the intermediate node 5-2. This modulated backscattered D2R signal 20-3 (or at least the information encoded in it), once received by the intermediate node 5-2, may be relayed / forwarded (transmitted) to the RAN node 5-1 in an uplink signal as part of the communication 20-4 between the intermediate node 5-2 and the RAN node 5-1. The modulated backscattered D2R signal 20-3 may be processed before being relayed by the intermediate node 5-2 to the RAN node 5-1. For example, the modulated D2R backscattered D2R signal 20-3 may be processed by the intermediate node 5-2 to extract information encoded in the modulated D2R backscattered signal, and to encapsulate the extracted information into an appropriate message format (e.g., in accordance with a corresponding application protocol) for communication with the RAN node 5-1. Alternatively, the modulated backscattered D2R signal may itself be processed by the intermediate node 5-2 (without extracting any data encoded in it) to encapsulate it into an appropriate message format (e.g., in accordance with a corresponding application protocol) for communication with the RAN node 5-1.

[0104] Such transmission of an unmodulated carrier, and receipt of backscattering by the same intermediate node 5-2 may, for example, be supported by topology 2 where full duplex operation is supported at that intermediate node 5-2.

[0105] Communication 20-4 between the RAN node 5-1 and the intermediate node 5-2 may occur over any appropriate interface. For example, the RAN node 5-1 and intermediate node 5-2 may communicate over an air interface (such as the Uu interface or the like), for example where the intermediate node 5-2 is a UE 3 (or at least acts like a UE in its communication with the RAN node 5-1). The RAN node 5-1 and intermediate node 5-2 may communicate over a direct base station to base station interface (such as X2 or Xn), for example where the intermediate node 5-2 is a base station (or at least acts like a base station in its communication with the RAN node 5-1). The RAN node 5-1 and intermediate node 5-2 may communicate over an appropriate IAB interface (such as F1), for example where the RAN node 5-1 acts as an IAB donor base station and the intermediate node 5-2 is an IAB node. Nevertheless, the RAN node 5-1 and the intermediate node 5-2 may communicate over a dedicated interface for the purpose of ambient IoT.

[0106] Nevertheless, while Fig. 3A shows the unmodulated carrier signal 20-1 (or CW) and the R2D signal 20-2 as originating from the same node; namely the intermediate node 5-2, it will be appreciated that topology 2 also allows for the possibility that the intermediate node 5-2 (in this case the 'IoT device reader') transmitting to and receiving from the A-IoT device 3-1 is a different communication node than a communication node that provides the unmodulated carrier signal 20-1 (or CW).

[0107] For example, as shown in Fig. 3B, which illustrates schematically a second possible arrangement of a second connectivity topology (topology 2) that may be used in the communication system 1, a separate communication node 6 may transmit an unmodulated carrier signal 20-1 (or CW) to the A-IoT device 3-1 to provide the A-IoT device 3-1 with a signal and / or energy based upon which modulated and backscattered / reflected information can be sent. Upon receiving an R2D signal 20-2 from the intermediate node 5-2 (which may be triggered in response to the intermediate node 5-2 receiving a DL transmission 20-4 from the RAN node 5-1) the A-IoT device 3-1 may modulate the unmodulated carrier signal 20-1 (or CW) that it received (e.g., based on the R2D signal 20-2 it received) and backscatter / reflect that modulated signal as a backscattered D2R signal 20-3, to the intermediate node 5-2.

[0108] Similarly to in Fig. 3A, the intermediate node 5-2 may then send / relay the modulated backscattered D2R signal 20-3 it receives from the A-IoT device 3-1 (or at least the information encoded in it), to the RAN node 5-1 in an uplink signal as part of the communication 20-4 between the intermediate node 5-2 and the RAN node 5-1. The modulated backscattered D2R signal 20-3 may be processed before being relayed by the intermediate node 5-2 to the RAN node 5-1. For example, the modulated backscattered D2R signal 20-3 may be processed by the intermediate node 5-2 to extract information encoded in the modulated backscattered D2R signal, and to encapsulate the extracted information into an appropriate message format (e.g., in accordance with a corresponding application protocol) for communication with the RAN node 5-1. Alternatively, the modulated backscattered D2R signal may itself be processed by the intermediate node 5-2 (without extracting any data encoded in it) to encapsulate it into an appropriate message format (e.g., in accordance with a corresponding application protocol) for communication with the RAN node 5-1.

[0109] It will be appreciated that in the arrangement of Fig. 3A and Fig. 3B, the intermediate node 5-2 may be of a type that attempts to demodulate the received backscattered signal for subsequent forwarding of the data to the RAN node 5-1 (e.g., a layer-2 (L2) relay device that attempts to demodulate any layer-1 (L1) signals that it receives). Such an intermediate node 5-2 may be referred to as be a layer 2 ('L2') type intermediate node 5-2. Nevertheless, the intermediate node 5-2 may be of a type that blindly forwards a received signal without attempting to demodulate it and hence, on receipt of the backscattered signal no attempt is made to demodulate it (e.g., an L1 repeater device or a network-controlled repeater (NCR) node). Such an intermediate node 5-2 may be referred to as be a layer 1 ('L1') type intermediate node 5-2.

[0110] Topology 2 may be deployed for scenarios with a type 1, 2a, and / or 2b A-IoT device 3-1, in which the A-IoT device 3-1 is in an indoor environment but the RAN node 5-1 is located in an outdoor environment. In this scenario the RAN node 5-1 may support one or more small cells (e.g., micro-cells) used for voice, video, and data transmission, which are designed to provide network coverage to small areas and operate on either licensed FDD, licensed TDD, or unlicensed parts of the spectrum. Alternatively, the RAN node 5-1 may support one or more larger cells (e.g., macro- cells) providing radio coverage to a large area, and that operate on either licensed FDD, licensed TDD, or unlicensed parts of the spectrum. In this scenario, the assisting node 5-2 may be located in an indoor or an outdoor environment.

[0111] Topology 2 may also be deployed for indoor scenarios with a type 1, 2a, and / or 2b A-IoT device 3-1, intermediate device 5-2, and RAN node 5-1 are located in an indoor environment. In this scenario the RAN node 5-1 typically supports one or more small cells (e.g., micro-, and pico- cells) used for voice, video, and data transmission, which are designed to provide network coverage to small areas and operate on either licensed FDD, licensed TDD, or unlicensed parts of the spectrum.

[0112] Topology 2 may also be deployed for outdoor scenarios with a type 1, 2a or 2b IoT device A-3-1, RAN node 5-1 and intermediate (or assisting) node 5-2 being located in an outdoor environment. In this scenario the RAN node 5-1 may support one or more small cells (e.g., micro-cells) used for voice, video, and data transmission, which are designed to provide network coverage to small areas and operate on either licensed FDD, licensed TDD, or unlicensed parts of the spectrum. Alternatively, the RAN node 5-1 may support one or more larger cells (e.g., macro- cells) providing radio coverage to a large area, and that operate on either licensed FDD, licensed TDD, or unlicensed parts of the spectrum.

[0113] This topology may, for example, be appropriate for a situation in which a RAN node 5-1 needs to fetch data (e.g., a meter record, a sensor reading, an error code and / or the like) from the A-IoT device 3-1. The RAN node 5-1 will trigger the intermediate node 5-2 to send an unmodulated carrier signal as a 'stimulus' signal to the A-IoT device 3-1 which will automatically respond with the required data encoded in the resulting backscattered / reflected signal. The resulting backscattered / reflected signal (or at least the data encoded in it) will then be forwarded / relayed to the RAN node 5-1.

[0114] Figs. 4A and 4B illustrate schematically a third connectivity topology (topology 3) of a mobile (cellular or wireless) communication system 1.

[0115] As shown in Figs. 4a and 4b, in topology 3 part of the functionality of an A-IoT device reader is implemented as part of an assisting node 5-2 and part of the functionality of the A-IoT device reader is implemented as part of a RAN node 5-1. Specifically, an A-IoT device 3-1 and the RAN node 5-1 engage in communication with one another via the assisting node 5-2 (which may also be referred to as an intermediate node). It will be appreciated that while the assisting node 5-2 is depicted in Fig. 4A and Fig. 4B as a type of base station, the assisting node 5-2 may in fact be any one of an IAB node, a UE 3, a repeater, or the like, or any other appropriate device that can act as an intermediary between a RAN node 5-1 and an A-IoT device 3-1.

[0116] It will be appreciated that the assisting node 5-2 may be of a type that attempts to demodulate the received backscattered signal for subsequent forwarding of the data to the RAN node 5-1 (e.g., a layer-2 (L2) relay device that attempts to demodulate any layer-1 (L1) signals that it receives). Such an assisting node may be referred to as be a layer 2 ('L2') type assisting node 5-2. Nevertheless, the assisting node 5-2 may be of a type that blindly forwards a received signal without attempting to demodulate it (e.g., an L1 repeater device or a network-controlled repeater (NCR) node) and hence, on receipt of the backscattered signal no attempt is made to demodulate it. Such an assisting node may be referred to as be a layer 1 ('L1') type assisting node 5-2.

[0117] As shown in Fig. 4A, the A-IoT device 3-1 may communicate with a RAN node 5-1 in a downlink direction and an assisting (intermediate) node 5-2 in an uplink direction (e.g., on a 'sidelink' or similar). The communication between the RAN node 5-1 and the A-IoT device 3-1, or the communication between the assisting node 5-2 and the A-IoT device 3-1 respectively may occur over an appropriate air interface. For example, they may communicate over a Uu or dedicated 'sidelink' interface.

[0118] In this example the RAN node 5-1 (base station / cell) is responsible for transmission of an unmodulated carrier signal 20-1 (or CW) to the A-IoT device 3-1 to provide the A-IoT device 3-1 with a signal and / or energy based upon which modulated and backscattered / reflected information can be sent. Upon receiving an R2D signal 20-2 from the RAN node 5-1, the unmodulated carrier signal 20-1 may be modulated (e.g., based on the received R2D signal 20-2) and backscattered, as a modulated backscattered D2R signal 20-3, from the A-IoT device 3-1 and received at the assisting node 5-2. That is, the assisting node 5-2 is responsible for receiving the backscattered D2R signal 20-3 from the A-IoT device 3-1. The modulated backscattered D2R signal 20-3 (or at least the information encoded in it), once received by the assisting node 5-2, may be relayed (forwarded / transmitted) to the RAN node 5-1 in another signal 20-3'. The modulated backscattered D2R signal 20-3 may be processed before being relayed / forwarded by the assisting node 5-2 to the RAN node 5-1. For example, the modulated backscattered 20-3 signal may be processed by the assisting node 5-2 to extract information encoded in the modulated backscattered signal, and to encapsulate the extracted information into an appropriate message format (e.g., in accordance with a corresponding application protocol) for communication with the RAN node 5-1 over an appropriate signal 20-3'. Alternatively, the modulated backscattered D2R signal 20-3 may itself be processed by the assisting node 5-2 (without extracting any data encoded in it) to encapsulate it into an appropriate message format (e.g., in accordance with a corresponding application protocol) for communication with the RAN node 5-1 over an appropriate signal 20-3'.

[0119] The communication 20-3' between the RAN node 5-1 and the assisting node 5-2 occurs over an appropriate interface. For example, the RAN node 5-1 and the assisting node 5-2 may communicate over an air interface (such as the Uu interface or the like), for example where the assisting node 5-2 is a UE 3 (or at least acts like a UE in its communication with the RAN node 5-1). The RAN node 5-1 and assisting node 5-2 may communicate over an appropriate IAB interface (such as F1), for example where the RAN node 5-1 acts as an IAB donor base station and the assisting node 5-2 is an IAB node. Nevertheless, the RAN node 5-1 and the assisting node 5-2 may communicate over a dedicated interface for the purpose of ambient IoT. The communication, comprising the modulated backscattered signal 20-2 received at the assisting node 5-2 from the A-IoT device 3-1, also occurs over an appropriate air interface. For example, they may communicate over a Uu or a dedicated interface.

[0120] This topology may, for example, be appropriate for a situation in which a RAN node 5-1 needs to fetch data (e.g., a meter record, a sensor reading, an error code and / or the like) from the A-IoT device 3-1. The RAN node 5-1 will send an unmodulated carrier signal as a 'stimulus' signal to the A-IoT device 3-1 which will automatically respond with the required data encoded in the resulting backscattered / reflected signal sent to the assisting node 5-2 for relaying / forwarding to the RAN node 5-1.

[0121] Alternatively, as shown in Fig. 4B, the A-IoT device 3-1 may communicate with a RAN node 5-1 in an uplink direction and an assisting (intermediate) node 5-2 in a downlink direction (e.g., on a 'sidelink' or similar). The communication between the RAN node 5-1 and A-IoT device 3-1, and the communication between the assisting node 5-2 and the A-IoT device 3-1, respectively occur over an appropriate air interface. For example, they may communicate over a Uu or dedicated 'sidelink' interface.

[0122] In this example the assisting node 5-2 is responsible for transmission of an unmodulated carrier signal 20-1 to the A-IoT device 3-1 to provide the A-IoT device 3-1 with a signal and / or energy based upon which modulated and backscattered / reflected information can be sent. Upon receiving an R2D signal 20-2 from the assisting node 5-2, the unmodulated carrier signal 20-1 may be modulated (e.g., based on the received R2D signal 20-2) and backscattered, as a modulated backscattered D2R signal 20-3, from the A-IoT device 3-1 and received at the RAN node 5-1. That is, the RAN node 5-1 (base station / cell) is responsible for receiving the backscattered D2R signal 20-3 from the A-IoT device 3-1. The transmission of the unmodulated carrier signal 20-1 may be triggered by a downlink signal 20-2' received by the assisting node 5-2 from the RAN node 5-1. For example, the downlink signal 20-2' may be (or may carry) the unmodulated carrier signal 20-1 that is to be transmitted (e.g. relayed) by the assisting node 5-2 to the A-IoT device 3-1 or may be a trigger signal for triggering transmission of the unmodulated carrier signal 20-1.

[0123] This topology may, for example, be appropriate for a situation in which a RAN node 5-1 needs to fetch data (e.g., a meter record, a sensor reading, an error code and / or the like) from the A-IoT device 3-1. The RAN node 5-1 will send an unmodulated carrier signal as a 'stimulus' signal to the IoT device 3-1 which will automatically respond with the required data encoded in the resulting backscattered / reflected signal sent to the assisting node 5-2. The resulting backscattered / reflected signal (or at least the data encoded in it) will then be forwarded / relayed to the RAN node 5-1 by the assisting node 5-2.

[0124] Similarly to Fig. 4A, in Fig. 4B the communication 20-2' between the RAN node 5-1 and the assisting node 5-2 occurs over an appropriate interface. For example, the RAN node 5-1 and the assisting node 5-2 may communicate over an air interface (such as the Uu interface or the like), for example where the assisting node 5-2 is a UE 3 (or at least acts like a UE in its communication with the RAN node 5-1). The RAN node 5-1 and assisting node 5-2 may communicate over an appropriate IAB interface (such as F1), for example where the RAN node 5-1 acts as an IAB donor base station and the assisting node 5-2 is an IAB node. Nevertheless, the RAN node 5-1 and the assisting node 5-2 may communicate over a dedicated interface for the purpose of ambient IoT. The downlink communication, comprising the unmodulated carrier signal 20-1 sent from the assisting node 5-2 to the A-IoT device 3-1, also occurs over an appropriate air interface. For example, they may communicate over a Uu or a dedicated interface.

[0125] This topology may, for example, be appropriate for a situation in which a RAN node 5-1 needs to fetch data (e.g., a meter record, a sensor reading, an error code and / or the like) from the A-IoT device 3-1. The RAN node 5-1 will trigger the assisting node 5-2 to send an unmodulated carrier signal as a 'stimulus' signal to the A-IoT device 3-1 which will automatically respond with the required data encoded in the resulting backscattered / reflected signal sent to the RAN node 5-1.

[0126] In either scenario (illustrated in Fig. 4A or 4B), backscattering may be supported even if the RAN node 5-1 and / or the assisting node 5-2 do not support full duplex operation.

[0127] <Duty-Cycle Monitoring (DCM) Operation> 　　Each A-IoT device 3-1 is configured to be able to employ a duty cycle mechanism / duty cycle monitoring (DCM) in which an A-IoT device 3-1 recurringly (at periodic or aperiodic intervals) operates in an 'ON' (or active) state for a (pre)configured (or possibly dynamically indicated) time period / duration (an 'on' or 'active' period) to monitor for R2D transmissions (e.g., random access (RA) triggers), before automatically entering (or being triggered to enter) a SLEEP (or 'OFF' or 'inactive') state for a (potentially different) time period / duration.

[0128] It will be appreciated that the duration of any SLEEP / OFF state may be variable, may be dynamically indicated, may be (pre)configured, or may be determined at the A-IoT device 3-1 based on A-IoT device specific considerations (e.g., the specific A-IoT device implementation, energy harvesting characteristics (e.g., energy harvesting rate / depletion rate, and or the like).

[0129] During the SLEEP / OFF state, the A-IoT device 3-1 may harvest (and store) RF energy from RF signals incident at the A-IoT device 3-1 (regardless of how strong those RF signals are).

[0130] It will be appreciated that the nature of the DCM employed (e.g., the number and functionality of the different DCM states / modes) may be different for different A-IoT devices / device types. For example, type 1 A-IoT devices 3-1 may be configured to use two discrete states / modes (e.g., 'ON' and 'OFF') whereas type 2 (2a and / or 2b) A-IoT devices 3-1 may be configured to use three discrete states / modes (e.g., 'ON', 'OFF', and 'SLEEP'). Whilst in an 'ON' state the A-IoT device 3-1 may, for example, be configured to support (at least) D2R transmission and R2D reception for the purposes of communication with the A-IoT device reader. On the other hand, whilst in an 'OFF' state, the A-IoT device 3-1 may be configured: not to support (at least) D2R transmission and R2D reception for the purposes of communication; but to support (at least) energy harvesting from incident A-IoT signals. Contrastingly, whilst in a 'SLEEP' state, the A-IoT device 3-1 may be configured: to support (at least) retention of (at least some) memory content from a previous ON state and maintenance of one or more timers (e.g., in addition to energy harvesting); but not to support (at least) D2R transmission.

[0131] A given duty cycle employed by the A-IoT device 3-1 implementing DCM may thus involve: recurring (periodic or aperiodic) transitions from an ON state to a SLEEP state and then back to the ON state with some memory being retained and possibly a clock kept running (this may be referred to as 'light-sleep' DCM); or periodic / aperiodic transitions from an ON state to an OFF state (in which no memory / timer is maintained) and then back to the ON state (this may be referred to as 'deep-sleep' DCM).

[0132] <A-IoT Device States and Transitions> 　　As mentioned above, an A-IoT device 3-1 of the communication system 1 may employ DCM in which the A-IoT device 3-1 recurringly (at periodic or aperiodic intervals) operates in an 'ON' (or active) state for a (pre)configured (or possibly dynamically indicated, or possibly randomly generated) time period / duration (an 'on' or 'active' period) to monitor for R2D transmissions (e.g., random access (RA) triggers) and / or perform transmission for D2R communication and / or reception for R2D communication, before automatically entering (or being triggered to enter) a sleep (or 'OFF' or 'inactive') state for a (potentially different) time period / duration. Similarly, the A-IoT device 3-1 in a 'SLEEP' (or 'OFF' or 'inactive') state may, after a time period / duration (or in response to appropriate signalling - e.g., a wake-up signal (WUS), or the like), transition back to an 'ON' (or active) state. In summary, A-IoT devices 3-1 may support: - Transitions from an 'ON' state to an 'OFF' state; - Transitions from an 'ON' state to an 'SLEEP' state; - Transitions from an 'OFF' state to an 'ON' state; and - Transitions from an 'SLEEP' state to an 'ON' state.

[0133] Additionally, given the energy expenditure associated with the A-IoT device 3-1 in a 'SLEEP' state, it will be appreciated that A-IoT devices 3-1 may also be able to support: - Transitions from a 'SLEEP' state to an 'OFF' state. For completeness, a summary of possible A-IoT device transitions is provided below in Table I, along with possible events that may trigger those transitions.

[0134] Table I: Possible state transitions that may be triggered at an A-IoT device 3-1, and possible events that may trigger those transitions.

[0135] Example timing structures for transitions of an A-IoT device 3-1 implementing DCM that may be implemented in the communication system 1 will now be briefly described with reference to Figs. 5a to 5d.

[0136] <Example ON-SLEEP Transitions> <Example #1> 　　Fig. 5A illustrates a possible timing structure for an ON-SLEEP transition (e.g., Transition No. 3 in Table I) of an A-IoT device 3-1 implementing DCM that may occur in the communication system 1. As shown in Fig. 5A, an A-IoT device 3-1 may initially be in an OFF state (e.g., OFF period 502) at the start of an i-th access / inventory round being performed by an A-IoT device reader (e.g., a RAN node 5-1, an intermediate node 5-2, or the like). For example, at the start of the i-th access / inventory round, a (target) A-IoT device 3-1 may be in the OFF state due to it having insufficient energy to maintain / retain its memory content.

[0137] Additionally (or alternatively), the A-IoT device 3-1 may be in the OFF state due to it having insufficient energy to perform other operations, and the like, associated with being in an ON (or SLEEP) state.

[0138] Additionally (or alternatively), the A-IoT device 3-1 may be in the OFF state due to no communications between the A-IoT device reader and the A-IoT device 3-1 being scheduled during the OFF period 502.

[0139] At some future time T1, the A-IoT device 3-1 may transition from an OFF state to an ON state for a period of time (e.g., ON period 504) in response to the occurrence of a triggering event to trigger a transition from an OFF state to an ON state. For example, the A-IoT device 3-1 may be triggered to transition from an OFF state to an ON state in response to the A-IoT device 3-1 being fully charged and / or in response to communications between the A-IoT device reader and the A-IoT device 3-1 being scheduled in the ON period 504.

[0140] As shown in Fig. 5A, around the same time as the transition of the A-IoT device 3-1 from an OFF state to an ON state (or sometime later during the ON period 504), the A-IoT device reader may transmit an RA trigger message at step S502a which may be detected / received by the A-IoT device 3-1. It will be appreciated that while Fig. 5A only shows a single RA trigger message sent by the A-IoT device reader, the A-IoT device reader, as it has no knowledge of the state of a targeted A-IoT device 3-1, may be broadcast recurringly (at periodic or aperiodic intervals) to allow reception / detection by the targeted A-IoT device 3-1 soon after its transition to an ON state.

[0141] Following successful reception of the RA trigger message at step S502a, during the ON period 504, the A-IoT device 3-1 may respond to the A-IoT device reader with an appropriate response message (e.g., a RACH preamble message, or the like) in pursuance of the triggered RA procedure (step S504a) between the A-IoT device 3-1 and the A-IoT device reader.

[0142] Having successfully completed an RA procedure with the A-IoT device 3-1, the A-IoT device reader may then begin to perform communications with the A-IoT device 3-1 (step S506a). For example, the A-IoT device reader may perform R2D transmissions to the A-IoT device 3-1, and the A-IoT device 3-1 may perform D2R transmissions to the A-IoT device reader.

[0143] At some time later (e.g., T2) the A-IoT device 3-1 may be triggered to transition from its ON state to a SLEEP state. For example, the A-IoT device 3-1 may be triggered to transition from its ON state to a SLEEP as set out in Table I above - Transition No. 3.

[0144] The A-IoT device 3-1 may then remain in its SLEEP state for a SLEEP period 506 (which may, as shown in Fig 5A, extend into one or more subsequent access / inventory rounds) until it is triggered again to transition to its ON (or OFF) state.

[0145] < Example #2> 　　Fig. 5B illustrates another possible timing structure for an ON-SLEEP transition e.g., Transition No. 3 in Table I) of an A-IoT device implementing DCM that may occur in the communication system 1.

[0146] The timing structure for triggering a RACH procedure shown in Fig. 5B is the same as that in Fig. 5A, save that a R2D monitoring duration is provided toward the end of the ON period 504 of the A-IoT device 3-1. That R2D monitoring duration may, for example, be set by an appropriate RRC parameter that indicates a start time (e.g., T_Minimum) and an end time (e.g., T_Maximum).

[0147] Following the s communications at S506b of the A-IoT device 3-1 may listen for further transmissions from the A-IoT device reader for a short period (e.g., based on a timer (pre)configured / (pre)defined for that A-IoT device) as illustrated by the short R2D monitoring duration in Fig. 5B, before transitioning from its ON to its SLEEP state. That short R2D monitoring duration may, for example, act as an implicit indication that communications between the A-IoT device 3-1 and the A-IoT device reader are about to end.

[0148] The A-IoT device 3-1 may then be triggered to transition from its ON state to its SLEEP state as set out in Table I above - Transition No. 3.

[0149] However, it will be appreciated that relying only on the triggering events to transition the A-IoT device 3-1 from its ON state to a SLEEP state described in the examples above with reference to Figs. 5a and 5b could result in unnecessary energy consumption and energy inefficiencies in the A-IoT system (e.g., when entering a SLEEP state is unnecessary).

[0150] <Example SLEEP-ON Transitions> <Example #3> 　　Fig. 5C illustrates a possible timing structure for a SLEEP-ON transition (e.g., Transition No. 5 in Table I) of an A-IoT device implementing DCM that may occur in the communication system 1 (e.g., following an earlier ON-SLEEP transition as illustrated in Fig. 5A) .

[0151] The timing structure for triggering a RACH procedure in the i-th access / inventory round shown in Fig. 5c is the same as the timing structure for triggering a RACH procedure in the i-th access / inventory round in Fig. 5A (it will, nevertheless, be appreciated that the timing structure for triggering a RACH procedure in the i-th access / inventory round illustrated in Fig. 5B is equally applicable). As such the description of steps in the i-th access / inventory round in Fig. 5A above applies equally to the steps in the i-th access / inventory round shown in Fig. 5C.

[0152] Having entered a SLEEP state, at some future time T3within a subsequent access / inventory round (e.g., (i+1)-th access / inventory round), the A-IoT device 3-1 may transition from its SLEEP state to an ON state. For example, at the time T3, the A-IoT device 3-1 may be triggered to transition from its SLEEP state to an ON state as set out in Table I above - Transition No. 5.

[0153] Having transitioned back to an ON state, around the same time as the transition of the A-IoT device 3-1 (or sometime later during the ON period 508), the A-IoT device reader may transmit an RA trigger message at step S502b which may be detected / received by the A-IoT device 3-1. It will be appreciated that while Fig. 5C only shows a single RA trigger message transmitted by the A-IoT device reader, the A-IoT device reader, as it has no knowledge of the state of a targeted A-IoT device 3-1, may be broadcasted recurringly (at periodic or aperiodic intervals) to allow reception / detection by the targeted A-IoT device 3-1 soon after its transition to an ON state.

[0154] Following successful reception of the RA trigger message at step S502b, during the ON period 508, the A-IoT device 3-1 may respond to the A-IoT device reader with an appropriate response message (e.g., a RACH preamble message, or the like) to trigger an RA procedure (step S504b) between the targeted A-IoT device 3-1 and the A-IoT device reader.

[0155] Having successfully completed an RA procedure with the A-IoT device 3-1, the A-IoT device reader may then begin to perform communications with the A-IoT device 3-1 (step S506b). For example, the A-IoT device reader may perform R2D transmissions to the A-IoT device 3-1, and the A-IoT device 3-1 may perform D2R transmissions to the A-IoT device reader.

[0156] It will be appreciated however that relying only on the example SLEEP-ON transition of the A-IoT device implementing DCM, where a SLEEP mode spans access / inventory rounds, as described above with reference to Fig. 5C could result in inefficiencies in the A-IoT system. In particular, the example SLEEP-ON transition requires the A-IoT device 3-1 to perform an RA procedure each time after transitioning from a SLEEP state to an ON state.

[0157] < Example #4> 　　Fig. 5d illustrates a further possible timing structure for a SLEEP-ON transition (e.g., Transition No. 5 in Table I) of an A-IoT device implementing DCM that may occur in the communication system 1 (e.g., following an earlier ON-SLEEP transition as illustrated in Fig. 5B).

[0158] The timing structure for triggering a RACH procedure in the i-th access / inventory round shown in Fig. 5D is the same as the timing structure for triggering a RACH procedure in the i-th access / inventory round in Fig. 5B (it will, nevertheless, be appreciated that the timing structure for triggering a RACH procedure in the i-th access / inventory round illustrated in Fig. 5A is equally applicable). As such the description of steps in the i-th access / inventory round in Fig. 5B above applies equally to the steps in the i-th access / inventory round shown in Fig. 5D.

[0159] Having entered a SLEEP state, at some future time T3substantially at (or possibly before) the starting time of a subsequent access / inventory round (e.g., (i+1)-th access / inventory round) the A-IoT device 3-1 may transition from its SLEEP state to an ON state. For example, at a time T3, the A-IoT device 3-1 may be triggered to transition from its SLEEP state to an ON state as set out in Table I above - Transition No. 5.

[0160] After having transitioned back to an ON state, the A-IoT device 3-1 may receive may a WUS message from the A-IoT device reader to wake-up the A-IoT device 3-1 and / or transmit an R2D trigger message at step S502c which may be detected / received by the A-IoT device 3-1.

[0161] Following successful reception of the WUS at step S502c, during the ON period 508, the targeted A-IoT device 3-1 may respond to the A-IoT device reader with an appropriate response message. For example, where the message sent at step S502c is a WUS, the A-IoT device 3-1 may immediately begin communicating with the A-IoT device reader at step S506c and does not need to perform a RA procedure.

[0162] It will be appreciated however that relying on the example SLEEP-ON transition of the A-IoT device implementing DCM where a SLEEP mode spans access / inventory rounds, as described above with reference to Fig. 5D may result in inefficiencies in the A-IoT system. In particular, the example SLEEP-ON transition requires the A-IoT device 3-1 to transition from SLEEP to ON when the start of a subsequent access / inventory round starts. This in turn means the A-IoT device 3-1 switches to its ON state even if a RA trigger message and / or WUS message is not scheduled for a while within the subsequent access / inventory round. That in turn can result in the A-IoT device 3-1 expending energy listening for a RA trigger message and / or WUS message too early.

[0163] <Example OFF-ON / ON-OFF Transitions for Multiple A-IoT devices> <Example #5> 　　Fig. 6 illustrates a possible timing structure for an OFF-ON / ON-OFF transitions (e.g., Transition No. 2 and Transition No. 4 in Table I) of an A-IoT device implementing DCM that may occur in the communication system 1.

[0164] As shown in Fig. 6, a first A-IoT device 3-11 may initially be in an OFF state (e.g., OFF period 602) at the start of an i-th access / inventory round being performed by an A-IoT device reader (e.g., a RAN node 5-1, an intermediate node 5-2, or the like). For example, at the start of an i-th access / inventory round, the first A-IoT device 3-11 may be in an OFF state due to it having insufficient energy to maintain / retain its memory content. Additionally (or alternatively), the first A-IoT device 3-11 may be in an OFF state due to it having insufficient energy to perform other operations, and the like, associated with being in an ON (or SLEEP) state.

[0165] At some future time T1-1, the first A-IoT device 3-11 may transition from an OFF state to an ON state for a period of time (e.g., ON period 604-1) in response to the occurrence of a triggering event to trigger a transition from an OFF state to an ON state. For example, the first A-IoT device 3-11 may be triggered to transition from an OFF state to an ON state in response to the A-IoT device 3-1 being fully charged.

[0166] As shown in Fig. 6, around the same time as the transition of the first A-IoT device 3-11 from an OFF state to an ON state (or sometime later during the ON period 604-1), the A-IoT device reader may transmit an RA trigger message at step S602a which may be detected / received by the first A-IoT device 3-11. It will be appreciated that while Fig. 6 only shows a single RA trigger message sent by the A-IoT device reader, the A-IoT device reader, as it has no knowledge of the state of a targeted first A-IoT device 3-11, may be broadcast recurringly (at periodic or aperiodic intervals) to allow reception / detection by the targeted first A-IoT device 3-11 soon after its transition to an ON state.

[0167] Following successful reception of the RA trigger message at step S602a, during the ON period 604-1, the first A-IoT device 3-11 may respond to the A-IoT device reader with an appropriate response message (e.g., a RACH preamble message, or the like) in pursuance of the triggered RA procedure between the targeted A-IoT device 3-1 and the A-IoT device reader (not shown).

[0168] Having successfully completed an RA procedure with the A-IoT device 3-1, the A-IoT device reader may then begin to perform communications with the A-IoT device 3-1 (not shown).

[0169] At some time later (e.g., T1-2) the first A-IoT device 3-11 may be triggered to transition to an OFF state for a period of time (e.g., OFF period 606-1). For example, the first A-IoT device 3-11 may be triggered to transition to an OFF state for a period of time - e.g., when it has insufficient energy to maintain its memory content for a prolonged period as set out in Table I above - Transition No. 4.

[0170] At some time after T1-3, once the first A-IoT device 3-11 has harvested energy / charged-up and has sufficient energy to perform operations associated with an ON state, the first A-IoT device 3-11 may be triggered to transition to an ON state for a period of time (e.g., ON period 608-1) as set out in Table I above - Transition No. 2.

[0171] As shown in Fig. 6, around the same time as the transition of the first A-IoT device 3-11 from an OFF state to an ON state (or sometime later during the ON period 608-1), the A-IoT device reader may transmit an R2D trigger message at step S602d which may be detected / received by the first A-IoT device 3-11.

[0172] Following successful reception of the RA trigger message at step S602d, during the ON period 604-1, the targeted first A-IoT device 3-11 may respond to the A-IoT device reader with an appropriate response message (e.g., a RACH preamble message, or the like) in pursuance of the triggered RA procedure between the targeted first A-IoT device 3-11 and the A-IoT device reader (not shown).

[0173] Having successfully completed an RA procedure with the first A-IoT device 3-11, the A-IoT device reader may then begin to perform communications with the first A-IoT device 3-11 (not shown).

[0174] Once again, at some time later (e.g., T1-4) the first A-IoT device 3-11 may be triggered to, once again, transition to an OFF state for a period of time (e.g., OFF period 610-1) - e.g., when it has insufficient energy to maintain its memory content for a prolonged period as set out in Table I above - Transition No. 4.

[0175] Similarly, as shown in Fig. 6, a second A-IoT device 3-12 may initially be in an OFF state (e.g., OFF period 602-2) at the start of an i-th access / inventory round being performed by the A-IoT device reader. For example, at the start of an i-th access / inventory round, the second A-IoT device 3-12 may be in an OFF state due to it having insufficient energy to maintain / retain its memory content. Additionally (or alternatively), the second (target) A-IoT device 3-12 may be in an OFF state due to it having insufficient energy to perform other operations, and the like, associated with being in an ON (or SLEEP) state.

[0176] At some future time T2-1, the second A-IoT device 3-12 may transition from an OFF state to an ON state for a period of time (e.g., ON period 604-2) as set out in Table I above - Transition No. 2.

[0177] As shown in Fig. 6, around the same time as the transition of the second A-IoT device 3-12 from an OFF state to an ON state (or sometime later during the ON period 604-2), the A-IoT device reader may transmit an RA trigger message at step S602b which may be detected / received by the second A-IoT device 3-12. It will be appreciated that while Fig. 6 only shows a single RA trigger message sent by the A-IoT device reader, the A-IoT device reader, as it has no knowledge of the state of a targeted second A-IoT device 3-12, may be broadcasted recurringly (at periodic or aperiodic intervals) to allow reception / detection by the targeted second A-IoT device 3-12 soon after its transition to an ON state.

[0178] Following successful reception of the RA trigger message at step S602b, during the ON period 604-2, the second A-IoT device 3-12 may respond to the A-IoT device reader with an appropriate response message (e.g., a RACH preamble message, or the like) to trigger an RA procedure between the second A-IoT device 3-12 and the A-IoT device reader (not shown).

[0179] Having successfully completed an RA procedure with the second A-IoT device 3-12, the A-IoT device reader may then begin to perform communications with the second A-IoT device 3-12 (not shown).

[0180] At some time later (e.g., T2-2) the second A-IoT device 3-12 may be triggered to transition to an OFF state for a period of time (e.g., OFF period 606-2) as set out in Table I above - Transition No. 4 - e.g., when it has insufficient energy to maintain its memory content for a prolonged period.

[0181] At some time after T2-3, once the second A-IoT device 3-12 has harvested energy / charged-up and has sufficient energy to perform operations associated with an ON state, the second A-IoT device 3-12 may be triggered to transition to an ON state for a period of time (e.g., ON period 608-2) as set out in Table I above - Transition No. 2.

[0182] As shown in Fig. 6, around the same time as the transition of the second A-IoT device 3-12 from an OFF state to an ON state (or sometime later during the ON period 608-2), the A-IoT device reader may transmit an RA trigger message at step S602c which may be detected / received by the second A-IoT device 3-12.

[0183] Following successful reception of the RA trigger message at step S602c, during the ON period 604-2, the targeted second A-IoT device 3-12 may respond to the A-IoT device reader with an appropriate response message (e.g., a RACH preamble message, or the like) in pursuance of the triggered RA procedure between the targeted second A-IoT device 3-12 and the A-IoT device reader (not shown).

[0184] Having successfully completed an RA procedure with the second A-IoT device 3-12, the A-IoT device reader may then begin to perform communications with the second A-IoT device 3-12 (not shown).

[0185] Once again, at some time later (e.g., T2-4) the second A-IoT device 3-12 may be triggered to one again transition to an OFF state for a period of time (e.g., OFF period 610-2) as set out in Table I above - Transition No. 4 - e.g., when it has insufficient energy to maintain its memory content for a prolonged period.

[0186] However, it will be appreciated that relying on the example OFF-ON / ON-OFF transitions for multiple A-IoT devices implementing DCM in between access / inventory rounds described above with reference to Fig. 6 may result in inefficiencies in the A-IoT system.

[0187] For example, while it may be preferable for an A-IoT device 3-1 to transition from an ON state to an OFF state when the A-IoT device 3-1 does not have sufficient energy to maintain the content of its memory when the period between access / inventory rounds and / or subsequent communications is large, when the period between access / inventory rounds and / or subsequent communications is small, a transition from an ON state to an OFF state may not be necessary as, despite a low amount of energy, the A-IoT device 3-1 may be able to maintain its memory content long enough to facilitate the subsequent communications.

[0188] <Summary of Issues associated with Examples #1-#5> 　　Beneficially the communication system 1 is configured to support one or more enhanced techniques / mechanisms for providing potential energy savings and / or reduced transmissions - for example in the context of ON-SLEEP, SLEEP-ON, OFF-ON, and / or ON-OFF transitions of an A-IoT device implementing DCM.

[0189] Beneficially, for example, the communications system 1 may be configured to support one or more techniques / mechanisms for selectively inhibiting A-IoT devices that are capable of using three discrete states / modes (e.g., 'ON', 'OFF', and 'SLEEP') - whether type 1 or type 2 - from entering their SLEEP state even when the A-IoT devices would otherwise enter a SLEEP state (as described above).

[0190] Beneficially, the communications system 1 may be additionally (or alternatively) configured to support one or more triggering events for triggering an A-IoT device to transition to an OFF state even when the A-IoT device has sufficient energy to support operations associated with its SLEEP state.

[0191] A number of these possible mechanisms / techniques that may be implemented in the communication system 1 will now be briefly introduced, by way of example only, before a more detailed description of the various mechanisms / techniques is provided.

[0192] It will be appreciated that while the various examples introduced above and described in more detail later may be implemented in the communication system 1 without implementing the others, they are not mutually exclusive. For example, different options may be used at different times or in different circumstances depending on current conditions in the network, the capability of the targeted A-IoT devices, the number of targeted A-IoT devices, and / or other factors.

[0193] For example, as described in more detail later, the communication system 1 may be configured to support one or more procedures that allow the network to selectively enable and disable a SLEEP state of A-IoT devices that are configured to use three discrete states / modes (e.g., 'ON', 'OFF', and 'SLEEP'). The one or more procedures may, for example, comprise a procedure to allow an A-IoT device reader (or some other device in the network) to selectively enable / disable a SLEEP state of A-IoT devices based on one or more criteria (e.g., device type, energy status, task situation, Reader scheduling, etc.).

[0194] Beneficially, as described in more detail later, the communication system 1 may additionally (or alternatively) be configured to support one or more procedures that allow an A-IoT device 3-1 to transition to an OFF state even when the status of the A-IoT device 3-1 and / or paging provided to the A-IoT device 3-1 and / or scheduling information provided to the A-IoT device 3-1 would typically trigger the A-IoT device 3-1 to transition to a SLEEP state.

[0195] Beneficially, as described in more detail later, the communication system 1 may additionally (or alternatively) be configured to support one or more procedures that allow an A-IoT device 3-1 to transition to an ON state from a SLEEP state that reduces the complexity of the transition and reduces energy consumption of the A-IoT device 3-1.

[0196] Beneficially, as described in more detail later, the communication system 1 may additionally (or alternatively) be configured to support one or more procedures that allow an A-IoT device 3-1 to transition to a SLEEP state from an ON state when subsequent access / inventory rounds and scheduled communications are close together in time.

[0197] The various mechanisms / techniques will now be described in further detail, by way of example only, with reference to Figs. 7 to 11.

[0198] <Selective SLEEP State Enablement> 　　Fig. 7 illustrates a simplified sequence diagram of a procedure for selectively enabling / disabling a SLEEP state of an A-IoT device configured to use three discrete states / modes (e.g., 'ON', 'OFF', and 'SLEEP') that may be implemented in the communication system of Fig. 1.

[0199] As shown in Fig. 7, there is provided a RAN node 5-1 or an intermediate / assisting node 5-2 in communication with an A-IoT device 3-1. The RAN node 5-1 or the intermediate / assisting node 5-2 operates as an A-IoT device reader, and in the case where an intermediate / assisting node 5-2 operates as the A-IoT device reader, the intermediate / assisting node 5-2 may, for example, be an intermediate / assisting RAN node, an intermediate / assisting UE, or the like.

[0200] At step S702, the A-IoT device reader (e.g., RAN node 5-1; intermediate node 5-2) determines to enable (or disable) use of a SLEEP state by an A-IoT device 3-1. For example, the A-IoT device reader may determine whether to trigger the enablement (or disablement) of the use of a SLEEP state by an A-IoT device 3-1 configured to use three discrete states / modes (e.g., 'ON', 'OFF', and 'SLEEP') based on one or more criteria.

[0201] For example, the A-IoT device reader may determine to trigger enablement (or disablement) of the use of a SLEEP state by an A-IoT device 3-1 based on a device type of the A-IoT device 3-1. For example, where the A-IoT device 3-1 is a type 1 A-IoT device configured to use three discrete states / modes (e.g., 'ON', 'OFF', and 'SLEEP'), the A-IoT device reader may nevertheless determine that irrespective of the A-IoT device being able to support three discrete states / modes, the SLEEP state of the A-IoT device 3-1 should be disabled / deactivated.

[0202] Similarly, where the A-IoT device 3-1 is a type 1 A-IoT device configured to use three discrete states / modes (e.g., 'ON', 'OFF', and 'SLEEP'), the A-IoT device reader may determine to enable / activate the SLEEP state of the A-IoT device 3-1 when deployed in specific situations.

[0203] In another example, the A-IoT device reader may determine to trigger enablement (or disablement) of the use of a SLEEP state by an A-IoT device 3-1 based on an energy status of the A-IoT device 3-1. For example, where the A-IoT device 3-1 needs to conserve its stored energy, despite the A-IoT device 3-1 having sufficient energy to perform operations in a SLEEP state, the A-IoT device reader may nevertheless disable / deactivate the SLEEP state of the A-IoT device 3-1 to help conserve energy at the A-IoT device 3-1.

[0204] In yet another example, the A-IoT device reader may determine to trigger enablement (or disablement) of the use of a SLEEP state by an A-IoT device 3-1 based on a current (or future) task situation of the A-IoT device 3-1. For example, where the end of a task by an A-IoT device 3-1 is due to occur a short time prior to the beginning of a subsequent task, the A-IoT device reader may active / enable the SLEEP state of the A-IoT device 3-1 to enable the A-IoT device 3-1 to enter a sleep state in between those tasks, thereby avoiding the need for a full RA trigger procedure to be performed at the start of the subsequent task (e.g., a WUS signal instead may be used, and the A-IoT device 3-1 may use the information stored in its memory to begin performing subsequent tasks).

[0205] In yet another example, the A-IoT device reader may determine to trigger enablement (or disablement) of the use of a SLEEP state by an A-IoT device 3-1 based on scheduling of tasks, data transmissions, and the like, between the A-IoT device reader and the A-IoT device 3-1.

[0206] It will be appreciated that the scenarios described above where the A-IoT device reader determines to trigger enablement (or disablement) of the use of a SLEEP state by an A-IoT device 3-1 are by way of example only and that other scenarios may arise that cause the A-IoT device reader to trigger enablement (or disablement) of the use of a SLEEP state by the A-IoT device 3-1.

[0207] Having determined / decided to trigger enablement (or disablement) of the use of a SLEEP state by an A-IoT device 3-1 at step S702, the A-IoT device reader may send an appropriate message / indication to the A-IoT device 3-1 (e.g., a SLEEP state enable / disable message / indication, or the like) to activate / deactivate the use of a SLEEP state by an A-IoT device 3-1.

[0208] For example, the A-IoT device reader may send the SLEEP state enable / disable message, or the like, to the A-IoT device 3-1 dynamically via layer-1 (L1) signalling. For example, the A-IoT device reader may send an appropriate enable / disable indication to activate / deactivate a SLEEP state of the A-IoT device 3-1 via L1 control information sent by the A-IoT device reader to the A-IoT device 3-1.

[0209] In another example, the A-IoT device reader may send the SLEEP state activation / deactivation message, or the like, to the A-IoT device 3-1 semi-statically via MAC layer signalling between the A-IoT device 3-1 and the A-IoT device reader. For example, the A-IoT device reader may send an appropriate enable / disable indication to activate / deactivate a SLEEP state of the A-IoT device 3-1 via a MAC control element (CE).

[0210] In yet another example, the A-IoT device reader may send the SLEEP state enable / disable message, or the like, to the A-IoT device 3-1 periodically via higher layer signalling.

[0211] Having received the appropriate message / indication (e.g., a SLEEP state enable / disable message / indication, or the like) to activate / deactivate the use of a SLEEP state by an A-IoT device 3-1 at step S704, the A-IoT device 3-1 activates / deactivates its SLEEP state.

[0212] At step S706, having activated / deactivate the use of a SLEEP state in response to receiving the appropriate message / indication (e.g., a SLEEP state enable / disable message / indication, or the like) at step S704, the A-IoT device 3-1 may (optionally) send an appropriate response message / indication to the A-IoT device reader to confirm the activation / deactivation of the SLEEP state of the A-IoT device 3-1.

[0213] <Transition State Enhancements> 　　It will be appreciated the transition state enhancements described below may, where appropriate, be combined with the selective SLEEP state enablement procedure described above with reference to Fig. 7.

[0214] Fig. 8A illustrates an example timing structure for an ON-OFF transition procedure that may be performed by an A-IoT device implementing DCM in the communication system 1.

[0215] As shown in Fig. 8A, an A-IoT device 3-1 may initially be in an OFF state (e.g., OFF period 802) at the start of an i-th access / inventory round being performed by an A-IoT device reader (e.g., a RAN node 5-1, an intermediate node 5-2, or the like). For example, at the start of an i-th access / inventory round, an A-IoT device 3-1 may be in the OFF state due to it having insufficient energy to maintain / retain its memory content.

[0216] Additionally (or alternatively), the A-IoT device 3-1 may be in the OFF state due to it having insufficient energy to perform other operations, and the like, associated with being in an ON (or SLEEP) state.

[0217] Additionally (or alternatively), the A-IoT device 3-1 may be in an OFF state due to no communications between the A-IoT device reader and the A-IoT device 3-1 being scheduled during the OFF period 802.

[0218] At some future time T1, an A-IoT device 3-1 may transition from an OFF state to an ON state for a period of time (e.g., ON period 804) in response to the occurrence of a triggering event to trigger a transition from an OFF state to an ON state. For example, the A-IoT device 3-1 may be triggered to transition from an OFF state to an ON state in response to the A-IoT device 3-1 being fully charged. For example, the A-IoT device 3-1 may be triggered to transition from an OFF state to an ON state as set out in Table I above - Transition No. 2 e.g., the A-IoT device 3-1 is fully charged.

[0219] As shown in Fig. 8A, around the same time as the transition of the A-IoT device 3-1 from an OFF state to an ON state (or sometime later during the ON period 804), the A-IoT device reader may transmit an RA trigger message at step S802 which may be detected / received by the A-IoT device 3-1. It will be appreciated that while Fig. 8A only shows a single RA trigger message sent by the A-IoT device reader, the A-IoT device reader, as it has no knowledge of the state of a targeted A-IoT device 3-1, may be broadcast recurringly (at periodic or aperiodic intervals) to allow reception / detection by the targeted A-IoT device 3-1 soon after its transition to an ON state.

[0220] Following successful reception of the RA trigger message at step S802, during the ON period 804, the targeted A-IoT device 3-1 may respond to the A-IoT device reader with an appropriate response message (e.g., a RACH preamble message, or the like) in pursuance of the triggered RA procedure (step S804) between the A-IoT device 3-1 and the A-IoT device reader.

[0221] Having successfully completed an RA procedure with the A-IoT device 3-1, the A-IoT device reader may then begin to perform communications with the A-IoT device 3-1 (step S806). For example, the A-IoT device reader may perform R2D transmissions to the A-IoT device 3-1, and the A-IoT device 3-1 may perform D2R transmissions to the A-IoT device reader.

[0222] During those communication with the A-IoT device 3-1, a message including an appropriate indication to indicate to the A-IoT device 3-1 that communications with the A-IoT device reader are about to ended (e.g., an 'End' indication) is sent to the A-IoT device 3-1. That 'End' indication may, for example, indicate that communications between the A-IoT device 3-1 and the A-IoT device reader will end in at a specific time, or after a specific time period has elapsed from receipt of the 'End' indication.

[0223] Additionally, during the communications between the A-IoT device 3-1 and the A-IoT device reader, another message (or the same message including the 'End' indication) may include a 'Disable' indication to disable the A-IoT device 3-1 from utilising a SLEEP state. For example, where the A-IoT device 3-1 is capable of operating with three states / modes (e.g., 'ON', 'OFF', or 'SLEEP'), the A-IoT device reader may provide an indication to the A-IoT device 3-1 toward the end of their communications to effectively disable the SLEEP state (e.g., to cause the A-IoT device 3-1 to operate with two states only (e.g., 'ON', and / or 'OFF')).

[0224] At some time later (e.g., T2) the A-IoT device 3-1 may be triggered to transition from its ON state to an OFF state for a period of time (OFF period 806) irrespective of whether the triggering event corresponds to an event listed against Transition No. 2 or 3 in Table I above. That is to say, as the SLEEP state of the A-IoT device 3-1 is disabled, the A-IoT device 3-1 may transition from an ON state to an OFF state only in response to a triggering event listed against Transition No. 2 or 3 in Table I above.

[0225] By transitioning to its OFF state, the A-IoT device 3-1 clears its memory content and clock, and may also disable functionality of the A-IoT device 3-1 associated with listening for, and receiving, a WUS from an A-IoT device reader.

[0226] Unlike in the transition described above with reference to Fig. 5A and / or Fig. 5B, by disabling the SLEEP state of the A-IoT device 3-1 as described above, an A-IoT device reader can force the A-IoT device 3-1 to transition to an OFF state once communications with the A-IoT device reader have finished even when the A-IoT device 3-1 has sufficient energy to transition to a SLEEP state once communications with the A-IoT device reader have finished. That in turn beneficially provides energy consumption savings at the A-IoT device 3-1.

[0227] It will be appreciated that although it is described above that the 'Disable' indication may be sent to the A-IoT device 3-1 during a communication with the A-IoT device reader at S806, when the procedure of Fig. 8A is combined with that of Fig. 7, the 'Disable' indication may be sent to the A-IoT device 3-1 in a dedicated SLEEP State Disable Message prior to the communications at S806.

[0228] Fig. 8B illustrates an example timing structure for an ON-SLEEP transition procedure that may be performed by an A-IoT device implementing DCM in the communication system 1.

[0229] As shown in Fig. 8B, an A-IoT device 3-1 may initially be in an OFF state (e.g., OFF period 802) at the start of an i-th access / inventory round being performed by an A-IoT device reader (e.g., a RAN node 5-1, an intermediate node 5-2, or the like). For example, at the start of an i-th access / inventory round, an A-IoT device 3-1 may be in the OFF state due to it having insufficient energy to maintain / retain its memory content.

[0230] Additionally (or alternatively), the A-IoT device 3-1 may be in the OFF state due to it having insufficient energy to perform other operations, and the like, associated with being in an ON (or SLEEP) state.

[0231] Additionally (or alternatively), the A-IoT device 3-1 may be in an OFF state due to no communications between the A-IoT device reader and the A-IoT device 3-1 being scheduled during the OFF period 802.

[0232] At some future time T1, an A-IoT device 3-1 may transition from an OFF state to an ON state for a period of time (e.g., ON period 814) in response to the occurrence of a triggering event to trigger a transition from an OFF state to an ON state. For example, the A-IoT device 3-1 may be triggered to transition from an OFF state to an ON state in response to the A-IoT device 3-1 being fully charged. For example, the A-IoT device 3-1 may be triggered to transition from an OFF state to an ON state as set out in Table I above - Transition No. 2 e.g., the A-IoT device 3-1 is fully charged.

[0233] As shown in Fig. 8B, around the same time as the transition of the A-IoT device 3-1 from an OFF state to an ON state (or sometime later during the ON period 814), the A-IoT device reader may transmit an RA trigger message at step S812 which may be detected / received by the A-IoT device 3-1. It will be appreciated that while Fig. 8B only shows a single RA trigger message sent by the A-IoT device reader, the A-IoT device reader, as it has no knowledge of the state of a targeted A-IoT device 3-1, may be broadcast recurringly (at periodic or aperiodic intervals) to allow reception / detection by the targeted A-IoT device 3-1 soon after its transition to an ON state.

[0234] Following successful reception of the RA trigger message at step S812, during the ON period 804, the targeted A-IoT device 3-1 may respond to the A-IoT device reader with an appropriate response message (e.g., a RACH preamble message, or the like) in pursuance of the triggered RA procedure (step S814) between the A-IoT device 3-1 and the A-IoT device reader.

[0235] Having successfully completed an RA procedure with the A-IoT device 3-1, the A-IoT device reader may then begin to perform communications with the A-IoT device 3-1 (step S816). For example, the A-IoT device reader may perform R2D transmissions to the A-IoT device 3-1, and the A-IoT device 3-1 may perform D2R transmissions to the A-IoT device reader.

[0236] During those communication with the A-IoT device 3-1, a message including an appropriate indication to indicate to the A-IoT device 3-1 that communications with the A-IoT device reader are about to ended (e.g., an 'End' indication) is sent to the A-IoT device 3-1. That 'End' indication may, for example, indicate that communications between the A-IoT device 3-1 and the A-IoT device reader will end in at a specific time, or after a specific time period has elapsed from receipt of the 'End' indication.

[0237] Additionally, during the communications between the A-IoT device 3-1 and the A-IoT device reader, another message (or the same message including the 'End' indication) may include a 'Enable' indication to enable the A-IoT device 3-1 from utilising a SLEEP state. For example, where the A-IoT device 3-1 is capable of operating with three states / modes (e.g., 'ON', 'OFF', or 'SLEEP'), the A-IoT device reader may provide an indication to the A-IoT device 3-1 toward the end of their communications to effectively enable the SLEEP state (e.g., to cause the A-IoT device 3-1 to operate with all three states).

[0238] At some time later (e.g., T2) the A-IoT device 3-1 may be triggered to transition from its ON state to a SLEEP state for a period of time (SLEEP period 816).

[0239] By transitioning to its SLEEP state, the A-IoT device 3-1 can maintain its memory content and clock, and may be able to maintain functionality of the A-IoT device 3-1 associated with listening for, and receiving, a WUS from an A-IoT device reader.

[0240] Fig. 9 illustrates an example timing structure for an enhanced ON-SLEEP / SLEEP-ON transition procedure that may be performed by a A-IoT device implementing DCM in the communication system 1.

[0241] As shown in Fig. 9, an A-IoT device 3-1 may initially be in an OFF state (e.g., OFF period 902) at the start of an i-th access / inventory round being performed by an A-IoT device reader (e.g., a RAN node 5-1, an intermediate node 5-2, or the like). For example, at the start of an i-th access / inventory round, an A-IoT device 3-1 may be in an OFF state due to it having insufficient energy to maintain / retain its memory content.

[0242] Additionally (or alternatively), the A-IoT device 3-1 may be in an OFF state due to it having insufficient energy to perform other operations, and the like, associated with being in an ON (or SLEEP) state.

[0243] Additionally (or alternatively), the A-IoT device 3-1 may be in an OFF state due to no communications between the A-IoT device reader and the A-IoT device 3-1 being scheduled during the OFF period 902.

[0244] At some future time T1, the A-IoT device 3-1 may transition from an OFF state to an ON state for a period of time (e.g., ON period 904) in response to the occurrence of a triggering event to trigger a transition from an OFF state to an ON state. For example, the A-IoT device 3-1 may be triggered to transition from an OFF state to an ON state in response to the A-IoT device 3-1 being fully charged. For example, the A-IoT device 3-1 may be triggered to transition from an OFF state to an ON state as set out in Table I above - Transition No. 2 e.g., the A-IoT device 3-1 is fully charged.

[0245] As shown in Fig. 9, around the same time as the transition of the A-IoT device 3-1 from an OFF state to an ON state (or sometime later during the ON period 904), the A-IoT device reader may broadcast an RA trigger message at step S902 which may be detected / received by the A-IoT device 3-1. It will be appreciated that while Fig. 9 only shows a single RA trigger message broadcast by the A-IoT device reader, the A-IoT device reader, as it has no knowledge of the state of a targeted A-IoT device 3-1, may be broadcasted periodically to allow reception / detection by the targeted A-IoT device 3-1 soon after its transition to an ON state.

[0246] Following successful reception of the RA trigger message at step S902, during the ON period 904, the targeted A-IoT device 3-1 may respond to the A-IoT device reader with an appropriate response message (e.g., a RACH preamble message, or the like) in pursuance of the triggered RA procedure (step S904) between the A-IoT device 3-1 and the A-IoT device reader.

[0247] Having successfully completed an RA procedure with the A-IoT device 3-1, the A-IoT device reader may then begin to perform communications with the A-IoT device 3-1 (step S906). For example, the A-IoT device reader may perform R2D transmissions to the A-IoT device 3-1, and the A-IoT device 3-1 may perform D2R transmissions to the A-IoT device reader.

[0248] During those communication with the A-IoT device 3-1, a message including an appropriate indication to indicate to the A-IoT device 3-1 that communications with the A-IoT device reader are about to ended (e.g., an 'End' indication) is sent to the A-IoT device 3-1. That 'End' indication may, for example, indicate that communications between the A-IoT device 3-1 and the A-IoT device reader will end in a specific time period from receipt of the 'End' indication.

[0249] Additionally, during the communications between the A-IoT device 3-1 and the A-IoT device reader, another message (or the same message including the 'End' indication) may include an 'Enable' indication to enable the A-IoT device 3-1 from utilising a SLEEP state. For example, where the A-IoT device 3-1 is capable of operating with three states / modes (e.g., 'ON', 'OFF', or 'SLEEP'), the A-IoT device reader may provide an indication to the A-IoT device 3-1 toward the end of their communications to effectively enable the SLEEP state (e.g., to cause the A-IoT device 3-1 to operate with three states (e.g., 'ON', 'OFF', and / or 'SLEEP')).

[0250] At some time later (e.g., T2) the A-IoT device 3-1 may be triggered to transition from its ON state to SLEEP state for a period of time (SLEEP period 906) as set out in Table I above - Transition No. 3.

[0251] Having entered a SLEEP state, at some future time T3, which is a time at which a subsequent communication (e.g., a WUS) in a subsequent access / inventory round (e.g., (i+1)-th access / inventory round) occurs, the A-IoT device 3-1 may be triggered to transition from its SLEEP state to an ON state as set out in Table I above - Transition No. 4.

[0252] By enabling the SLEEP state of the A-IoT device 3-1 as described above, and scheduling a WUS to coincide with a transition of the A-IoT device 3-1 from its SLEEP state to its ON state, the amount of time the A-IoT device 3-1 spends in its SLEEP state can be maximised (e.g., the A-IoT device 3-1 can be in its SLEEP state from the time indicated by the 'End' indication until a scheduled subsequent WUS). Accordingly, R2D monitoring occasions at the end of the communication at S906 are not required.

[0253] It will be appreciated that although it is described above that the 'Enable' indication may be sent to the A-IoT device 3-1 during a communication with the A-IoT device reader at S906, when the procedure of Fig. 9 is combined with that of Fig. 7, the 'Enable' indication may be sent to the A-IoT device 3-1 in a dedicated SLEEP State Enable Message prior to the communications at S906.

[0254] Fig. 10 illustrates an example timing structure for another enhanced ON-SLEEP / SLEEP-ON transition procedure that may be performed by an A-IoT device implementing DCM in the communication system 1.

[0255] As shown in Fig. 10, an A-IoT device 3-1 may initially be in an OFF state (e.g., OFF period 1002) at the start of an i-th access / inventory round being performed by an A-IoT device reader (e.g., a RAN node 5-1, an intermediate node 5-2, or the like). For example, at the start of an i-th access / inventory round, an A-IoT device 3-1 may be in an OFF state due to it having insufficient energy to maintain / retain its memory content.

[0256] Additionally (or alternatively), the A-IoT device 3-1 may be in an OFF state due to it having insufficient energy to perform other operations, and the like, associated with being in an ON (or SLEEP) state.

[0257] Additionally (or alternatively), the A-IoT device 3-1 may be in an OFF state due to no communications between the A-IoT device reader and the A-IoT device 3-1 being scheduled during the OFF period 1002.

[0258] At some future time T1, the A-IoT device 3-1 may transition from an OFF state to an ON state for a period of time (e.g., ON period 1004) in response to the occurrence of a triggering event to trigger a transition from an OFF state to an ON state. For example, the A-IoT device 3-1 may be triggered to transition from an OFF state to an ON state in response to the A-IoT device 3-1 being fully charged. For example, the A-IoT device 3-1 may be triggered to transition from an OFF state to an ON state as set out in Table I above - Transition No. 2 e.g., the A-IoT device 3-1 is fully charged.

[0259] As shown in Fig. 10, around the same time as the transition of the A-IoT device 3-1 from an OFF state to an ON state (or sometime later during the ON period 1004), the A-IoT device reader may broadcast an RA trigger message at step S1002 which may be detected / received by the A-IoT device 3-1. It will be appreciated that while Fig. 10 only shows a single RA trigger message broadcast by the A-IoT device reader, the A-IoT device reader, as it has no knowledge of the state of a targeted A-IoT device 3-1, may be broadcasted periodically to allow reception / detection by the targeted A-IoT device 3-1 soon after its transition to an ON state.

[0260] Following successful reception of the RA trigger message at step S1002, during the ON period 1004, the targeted A-IoT device 3-1 may respond to the A-IoT device reader with an appropriate response message (e.g., a RACH preamble message, or the like) in pursuance of the triggered RA procedure (not shown) between the A-IoT device 3-1 and the A-IoT device reader.

[0261] Having successfully completed an RA procedure with the A-IoT device 3-1, the A-IoT device reader may then begin to perform communications with the A-IoT device 3-1 (not). For example, the A-IoT device reader may perform R2D transmissions to the A-IoT device 3-1, and the A-IoT device 3-1 may perform D2R transmissions to the A-IoT device reader.

[0262] During those communication with the A-IoT device 3-1, a message including an appropriate indication to indicate to the A-IoT device 3-1 that communications with the A-IoT device reader are about to ended (e.g., an 'End' indication) is sent to the A-IoT device 3-1. That 'End' indication may, for example, indicate that communications between the A-IoT device 3-1 and the A-IoT device reader will end in a specific time period from receipt of the 'End' indication.

[0263] Additionally, during the communications between the A-IoT device 3-1 and the A-IoT device reader, another message (or the same message including the 'End' indication) may include an 'Enable' indication to enable the A-IoT device 3-1 from utilising a SLEEP state. For example, where the A-IoT device 3-1 is capable of operating with three states / modes (e.g., 'ON', 'OFF', or 'SLEEP'), the A-IoT device reader may provide an indication to the A-IoT device 3-1 toward the end of their communications to effectively enable the SLEEP state (e.g., to cause the A-IoT device 3-1 to operate with three states (e.g., 'ON', 'OFF', and / or 'SLEEP')).

[0264] At some time later (e.g., T2) the A-IoT device 3-1 may be triggered to transition from its ON state to SLEEP state for a period of time (SLEEP period 1006) as set out in Table I above - Transition No. 3.

[0265] Having entered a SLEEP state, at some future time T3, which is a time at which a subsequent communication (e.g., a WUS) in a subsequent access / inventory round (e.g., (i+1)-th access / inventory round) occurs (step S1004), the A-IoT device 3-1 may be triggered to transition from its SLEEP state to an ON state (ON period 1008) as set out in Table I above - Transition No. 4.

[0266] While in that ON period 1008, the A-IoT device 3-1 may perform further communications with the A-IoT device reader (step S1006) without requiring performance of a RA procedure, or the like (as the A-IoT device 3-1 can use its memory content to continue communications with the A-IoT device reader that it previously accessed in the i-th access / inventory round).

[0267] By enabling the SLEEP state of the A-IoT device 3-1 as described above, when the period between access / inventory rounds and / or subsequent communications is small, a transition from an ON state to a SLEEP state can be triggered, even if the A-IoT device 3-1 has a low amount of energy as the A-IoT device 3-1 may be able to maintain its memory content long enough to facilitate the subsequent communications.

[0268] It will be appreciated that although it is described above that the 'Enable' indication may be sent to the A-IoT device 3-1 during a communication with the A-IoT device reader at S1006, when the procedure of Fig. 10 is combined with that of Fig. 7, the 'Enable' indication may be sent to the A-IoT device 3-1 in a dedicated SLEEP State Enable Message prior to the communications at S1006.

[0269] Alternatively, when the procedure of Fig. 10 is combined with that of Fig. 7, and an 'Enable' indication may be sent to the A-IoT device 3-1 in a dedicated SLEEP State Enable Message prior to the communications at S1006, an 'Enable' indication may also be included in a communication sent by the A-IoT device reader to the A-IoT device 3-1 at step S1006 to indicate that a transition by the A-IoT device 3-1 from an ON state to a SLEEP state should be prioritised over a transition from an ON state to an OFF state.

[0270] <Other Possible Transition State Enhancements> 　　Fig. 11 illustrates a simplified sequence diagram of a procedure for indicating a paging periodicity offset to an A-IoT device for use in its transitions from a SLEEP state to an ON state.

[0271] It will be appreciated that the procedure of Fig. 11 may be combined with any of the procedures described above.

[0272] As shown in Fig. 11 there is provided an A-IoT device 3-1 in communication with an A-IoT device reader (e.g., a RAN node 5-1, an intermediate node 5-2, or the like). The procedure of Fig. 11 may begin with the A-IoT device 3-1 in an ON state.

[0273] As also shown in Fig. 11, the A-IoT device 3-1 may, optionally, be (pre)configured with information identifying a periodicity of paging messages (e.g., RA trigger messages) and, in effect, defining a corresponding SLEEP duration that indicates a length of time (i.e., duration) that the A-IoT device 3-1 may spend in a SLEEP state upon transition to a SLEEP state.

[0274] Alternatively (or additionally), at step S1102, the A-IoT device reader may optionally send an appropriate indication of the periodicity of paging messages to the A-IoT device 3-1 (in effect defining the corresponding SLEEP duration) when it is in its ON state.

[0275] Thus, at step S1103, the A-IoT device 3-1 may determine an appropriate SLEEP state duration based on the (pre)configured / indicated periodicity.

[0276] Sometime later, the A-IoT device reader may change a periodicity of paging indications sent to targeted A-IoT devices and thus the time that the A-IoT device 3-1 should ideally spend in its SLEEP state will change to compensate for the change in periodicity.

[0277] When the periodicity of paging indications has changed, the A-IoT device reader, at step S1104, may send an appropriate message or indication to the A-IoT device 3-1 to indicate a paging periodicity offset (e.g., relative to the (pe)configured / indicated periodicity or (optionally) to a current periodicity value) to the A-IoT device 3-1. It will nevertheless be appreciated that an indication of the paging periodicity offset may be provided recurringly (periodically or aperiodically) even when there has been no change in the periodicity of paging indications.

[0278] It will be appreciated that the indicated paging periodicity offset effectively represents an offset that may be applied to the SLEEP state duration previously determined at the A-IoT device 3-1 to change the SLEEP state duration to compensate for the change in periodicity of paging indications. That paging periodicity offset may take a variety of possible values. For example, the paging periodicity offset may have a value of zero when the periodicity of paging indications (and hence the ideal SLEEP state duration) remains unchanged relative to the (pre)configured / indicated value (or (optionally) a currently configured value) of periodicity.

[0279] In another example, the paging periodicity offset may have a positive value when the periodicity of paging indications (and hence the ideal SLEEP state duration) has increased relative to the (pre)configured / indicated value (or (optionally) a currently configured value) of periodicity. In yet another example, the paging periodicity offset may have a negative value when the periodicity of paging indications (and hence the ideal SLEEP state duration) has decreased relative to the (pre)configured / indicated value (or (optionally) a currently configured value) of periodicity.

[0280] That the paging periodicity offset may be transmitted to the A-IoT device 3-1 by the A-IoT device reader in an appropriate message or via appropriate signalling. For example, the paging periodicity offset may be transmitted to the A-IoT device 3-1 dynamically via layer-1 (L1) signalling e.g., via L1 control information.

[0281] In another example, the A-IoT device reader may send the appropriate paging periodicity offset to the A-IoT device 3-1 semi-statically via MAC layer signalling between the A-IoT device 3-1 and the A-IoT device reader. For example, the A-IoT device reader may send an appropriate paging periodicity offset to the A-IoT device 3-1 via a MAC control element (CE).

[0282] In yet another example, the A-IoT device reader may send the appropriate paging periodicity offset to the A-IoT device 3-1 periodically via higher layer signalling.

[0283] At step S1106, having received the paging periodicity offset indication from the A-IoT device reader, the A-IoT device 3-1 may determine (and set) a new SLEEP state duration i.e., a length of time that the A-IoT device 3-1 may spend in a SLEEP state upon transitioning to a SLEEP state. That new SLEEP state duration is determined by the A-IoT device 3-1 based on the (pre)configured / indicated periodicity value (or (optionally) a currently configured periodicity value) at the A-IoT device 3-1 and the paging periodicity offset indication received from the A-IoT device reader.

[0284] For example, at step S1106, the A-IoT device 3-1 may add the value indicated by the paging periodicity offset indication to its (pre)configured / indicated periodicity value (or (optionally) a currently configured periodicity value) for calculating the corresponding SLEEP state duration.

[0285] Sometime later (not shown) when the A-IoT device 3-1 is triggered to transition from an ON state to a SLEEP state, the A-IoT device 3-1 may trigger a countdown timer having an initial value that corresponds to the new SLEEP state duration. Upon expiry of that timer the A-IoT device 3-1 then transitions from its SLEEP state to an ON state (providing that the A-IoT device 3-1 has sufficient energy to support ON state operations / functions).

[0286] <Devices in the Communication System> <User Equipment> 　　Fig. 11 is a simplified block schematic illustrating the main components of a UE 3-2; 3-3 for implementation in the communication system 1. It will be appreciated that the UE 3-2; 3-3 may be configured to operate as an intermediate / assisting node 5-2 (i.e., and A-IoT device reader) in the communication system 1.

[0287] As shown, the UE 3-2; 3-3 has a transceiver circuit 31 that is operable to transmit signals to and to receive signals from a RAN node 5-1 via one or more antenna 33 (e.g., comprising one or more antenna elements). The UE 3 has a controller 37 to control the operation of the UE 3-2; 3-3. The controller 37 is associated with a memory 39 and is coupled to the transceiver circuit 31. Although not necessarily required for its operation, the UE 3-2; 3-3 might, of course, have all the usual functionality of a conventional UE (e.g., a user interface 35, such as a touch screen / keypad / microphone / speaker and / or the like for, allowing direct control by and interaction with a user) and this may be provided by any one or any combination of hardware, software, and firmware, as appropriate. Software may be pre-installed in the memory 39 and / or may be downloaded via the communication system or from a removable data storage device (RMD), for example.

[0288] The controller 37 is configured to control overall operation of the UE 3-2; 3-3 by, in this example, program instructions or software instructions stored within memory 39. As shown, these software instructions include, among other things, an operating system 41, and a communication control module 43.

[0289] The communication control module 43 is operable to control the communication between the UE 3-2; 3-3 and its serving RAN node or RAN nodes 5-1 (and other communication devices connected to the RAN node 5-1, such as further UEs 3 and / or core network nodes). The communication control module 43 is configured for the overall handling of uplink communication via associated uplink channels (e.g., via a physical uplink control channel (PUCCH), random access channel (RACH), and / or a physical uplink shared channel (PUSCH)) including both dynamic and semi-static signalling (e.g., SRS). The communication control module 43 is also configured for the overall handling of receipt of downlink communication via associated downlink channels (e.g., of DCI via a physical downlink control channel (PDCCH) and / or a physical downlink shared channel (PDSCH)) including both dynamic and semi-persistent scheduling (e.g., SPS). The communication control module 43 is responsible, for example: for determining where to monitor for downlink control information; for determining the resources to be used by the UE 3 for transmission / reception of UL / DL communication (including interleaved resources and resources subject to frequency hopping); for managing frequency hopping at the UE side; for determining how slots / symbols are configured (e.g., for UL, DL or full duplex communication, or the like); for determining which bandwidth parts are configured for the UE 3-2; 3-3; for determining how uplink transmissions should be encoded and the like.

[0290] Where the UE 3-2, 3-3 is configured to operate as an intermediate / assisting node 5-2 (i.e., as an A-IoT device reader) the communication control module 43 may be operable to control the communication between the A-IoT device 3-1 and the UE 3-2, 3-3, for example, via the associated physical channels (e.g., via a physical D2R channel (PDRCH), random access channel (RACH), and / or a physical R2D channel (PRDCH)).

[0291] It will be appreciated that the communication control module 43 may include a number of sub-modules ('layers' or 'entities') to support specific functionalities. For example, the UE 3-2, 3-3 may include sub-modules corresponding to the layers of a conventional protocol stack (PHY, MAC, RRC, RLC, PDCP etc.). Moreover, where the UE 3-2, 3-3 is configured to operate as an intermediate / assisting node 5-2, communication control module 43 may include sub-modules corresponding to the layers of a dedicated ambient IoT device protocol stack for controlling functions associated with those layers.

[0292] The communication control module 43 is configured, in particular, to control the UE's communication, where applicable, in accordance with any of the methods described herein.

[0293] <Ambient IoT device> Fig. 12 is a simplified block schematic illustrating the main components of an example of a UE comprising an ambient IoT device 3-1 for possible implementation in the communication system 1.

[0294] As shown, the ambient IoT device 3-1 (also referred to simply as an A-IoT device 3-1) has a transceiver circuit 331 that is operable to transmit signals to and to receive signals from a RAN node 5-1 (and / or an assisting node 5-2, and / or an intermediate node 5-2) via one or more antenna 333 (e.g., comprising one or more antenna elements).

[0295] The transceiver circuit 331 may comprise energy harvesting circuitry 331-1 that is configured to harvest and / or collect energy from an ambient energy source such as an incoming signal and / or other ambient sources of energy (e.g., of light, vibrations, or heat). That collected energy may then be provided to other modules of A-IoT device 3-1 to provide a stable power supply to those modules. The energy harvesting circuitry 331-1 may include, by way of example only, inductive and / or capacitive architectures to harvest energy from incoming signals.

[0296] It will however be appreciated that the energy harvesting circuitry 331-1 may alternatively not form part of the transceiver circuit 331, but instead is its own module. For example, this may be the case when the energy to be harvested does not originate from signals transmitted to the A-IoT device 3-1. By way of example only, the A-IoT device 3-1 may harvest energy from solar cells such as dye-sensitised solar cells (DSSCs).

[0297] The transceiver circuit 331 also has modulation circuitry 331-2 which modulates an incoming unmodulated carrier signal to the A-IoT device 3-1 to produce the modulated backscatter signal to be reflected from the IoT device 3-1 for receipt by another device. For example, the modulation circuitry 331-2 may be configured modulate an incoming RF signal to the A-IoT device 3-1 by altering the impedance or reflectivity of the A-IoT device 3-1 in response to receiving that incoming RF signal. The modulation circuitry 331-2 may be configured to modulate the incoming signal to encode data provided from one or more data sources 332. Typically, for example, the A-IoT device 3-1 may comprise a data source 332 in the form of a sensor (e.g., an optical, temperature, position sensor or the like) for providing measurement data or a sensor alert, may comprise a data source 332 in the form of a stored or hardwired parameter such as a device or device type identifier, and / or may comprise one or more other sources of data.

[0298] In this example, the transceiver circuit 331 may also have a signal amplifier 331-3 (which may utilise energy harvested by the energy harvesting circuitry 331-1) for amplifying any modulated backscattered signal to be reflected by the A-IoT device 3-1 for receipt at another device.

[0299] In this example, the A-IoT device 3-1 also has a controller 337 to control the overall operation of the A-IoT device 3-1. The controller 337 is associated with a memory 339 and is coupled to the transceiver circuit 331. Although not necessarily required for its operation, the A-IoT device 3-1 might, of course, have all the usual functionality of a more conventional UE (e.g., a user interface 335, such as a touch screen / keypad / microphone / speaker and / or the like for, allowing direct control by and interaction with a user) and this may be provided by any one or any combination of hardware, software, and firmware, as appropriate. Software may be pre-installed in the memory 339 and / or may be downloaded via the communication system 1 or from a removable data storage device (RMD), for example.

[0300] The controller 337 is configured to control overall operation of the A-IoT device 3-1 by, in this example, program instructions or software instructions stored within memory 339. As shown, these software instructions include, among other things, an operating system 341, and a communication control module 343.

[0301] The communication control module 343 is operable to control the communication between the A-IoT device 3-1, a RAN node 5-1, and / or an assisting node 5-2. The communication control module 343 may, for example, be configured for the overall handling of communication via associated physical channels (e.g., via a physical D2R channel (PDRCH), random access channel (RACH), and / or a physical R2D channel (PRDCH)).

[0302] It will be appreciated that the communication control module 343 may include a number of sub-modules ('layers' or 'entities') to support specific functionalities. For example, the communication control module 343 may include sub-modules corresponding to the layers of a dedicated ambient IoT device protocol stack for controlling functions associated with those layers.

[0303] The communication control module 343 is configured, in particular, to control the A-IoT device's communication, where applicable, in accordance with any of the methods described herein.

[0304] <RAN node> 　　Fig. 13 is a simplified block schematic illustrating the main components of a RAN node 5-1 (e.g., a base station / A-IoT device reader) for implementation in the communication system 1. It will be appreciated that the RAN node 5-1 may be configured to operate as an A-IoT device reader in the communication system 1.

[0305] As shown, the RAN node 5-1 has a transceiver circuit 51 for transmitting signals to and for receiving signals from the communication devices (such as UEs 3-2; 3-3, A-IoT devices 3-1, and possibly assisting or intermediate devices 5-2) via one or more antenna 53 (e.g., a single or multi-panel antenna array / massive antenna), and a core network interface 55 for transmitting signals to and for receiving signals from network nodes in the core network 7. Although not shown, the base station 5-1 may also be coupled to other base stations via an appropriate interface (e.g., the so-called 'X2' interface in LTE or the 'Xn' interface in NR). The RAN node 5-1 has a controller 57 to control the operation of the RAN node 5-1. The controller 57 is associated with a memory 59. Software may be pre-installed in the memory 59 and / or may be downloaded via the communication system 1 or from a removable data storage device (RMD), for example. The controller 57 is configured to control the overall operation of the RAN node 5-1 by, in this example, program instructions or software instructions stored within memory 59.

[0306] As shown, these software instructions include, among other things, an operating system 61, and a communication control module 63.

[0307] The communication control module 63 is operable to control the communication between the RAN node 5-1 and UEs 3 and other network entities (e.g., core network nodes) that communicate with the RAN node 5-1. The communication control module 63 is configured for the overall control of the reception and decoding of uplink communication, via associated uplink channels (e.g., via a physical uplink control channel (PUCCH), a random-access channel (RACH), and / or a physical uplink shared channel (PUSCH)) including both dynamic and semi-static signalling (e.g., SRS), and modulated backscattered communication in accordance with ambient IoT (where applicable). The communication control module 63 is also configured for the overall control of the transmission of downlink communication including downlink communication via associated downlink channels (e.g., via a physical downlink control channel (PDCCH) and / or a physical downlink shared channel (PDSCH)) including both dynamic and semi-persistent scheduling (e.g., SPS), and downlink communication of an unmodulated carrier signal in accordance with ambient IoT (where applicable). The communication control module 63 is responsible, for example: for determining where to configure the UE 3 to monitor for downlink control information (e.g., the location of search spaces, CORESETs, and associated PDCCH candidates to monitor); for determining the resources to be scheduled for UE transmission / reception of UL / DL communication (including interleaved resources and resources subject to frequency hopping); for managing frequency hopping at the base station side; for configuring slots / symbols appropriately (e.g., for UL, DL or full duplex communication, or the like); for configuring bandwidth parts for the UE 3; for providing related configuration signalling to a UE 3; and the like.

[0308] Where the RAN node 5-1 is configured to operate as an A-IoT device reader the communication control module 63 is operable to control the communication between the A-IoT device 3-1 and the RAN node 5-1, for example, via the associated physical channels (e.g., via a physical D2R channel (PDRCH), random access channel (RACH), and / or a physical R2D channel (PRDCH)) including both dynamic and semi-static signalling.

[0309] It will be appreciated that the communication control module 63 may include a number of sub-modules ('layers' or 'entities') to support specific functionalities. By way of example only the communication control module 63 may include sub-modules corresponding to the layers of a conventional protocol stack (PHY, MAC, RRC, RLC, PDCP etc.). Moreover, where the RAN node 5-1 is configured to operate as an A-IoT device reader, the communication control module 63 may include, sub-modules corresponding to the layers of a dedicated ambient IoT device protocol stack for controlling functions associated with those layers.

[0310] The communication control module 63 is configured in particular, to control the RAN node's communication, in accordance with any of the methods described herein.

[0311] <Assisting (or intermediate) node> 　　Fig. 14 is a simplified block schematic illustrating the main components of an example of an assisting (or intermediate) node 5-2 for possible implementation in the communication system 1.

[0312] As shown, the assisting node 5-2 may comprise a UE 3 (such as, or similar to, UE 3-2; 3-3), an IAB node, a repeater, or the like, which is capable of ambient IoT operation. In this scenario, the assisting node 5-2 has a transceiver circuit 151 that is operable to transmit signals to and to receive signals from a UE 3 (such as an ambient IoT device) via one or more antenna 153 (e.g., comprising one or more antenna elements), and a RAN interface 155 for transmitting signals to and for receiving signals from the RAN node 5-1 (which may also be over the air via the antenna 153, or via a different antenna).

[0313] The assisting node 5-2 has a controller 157 to control the operation of the assisting node 5-2. The controller 157 is associated with a memory 159 and is coupled to the transceiver circuit 151. Although not necessarily required for its operation, the assisting node 5-2 might, of course, have other functionality (e.g., a user interface, such as a touch screen / keypad / microphone / speaker and / or the like for, allowing direct control by and interaction with a user) and this may be provided by any one or any combination of hardware, software, and firmware, as appropriate. Software may be pre-installed in the memory 159 and / or may be downloaded via the communication system 1 or from a removable data storage device (RMD), for example.

[0314] The controller 157 is configured to control overall operation of the UE 3 by, in this example, program instructions or software instructions stored within memory 159. As shown, these software instructions include, among other things, an operating system 161, and a communication control module 163.

[0315] The communication control module 163 is operable to control the communication between the assisting node 5-2, the RAN node 5-1, and any IoT devices (including the ambient IoT device 3-1). The communication control module 163 is configured, in particular, for the overall handling of communication with the RAN node 5-1. For example, where the intermediate / assisting node 5-2 is a UE 3 (or at least operates like a UE in its communication with the RAN node 5-1) this uplink communication may be via associated uplink channels (e.g., via a physical uplink control channel (PUCCH), random access channel (RACH), and / or a physical uplink shared channel (PUSCH)) including both dynamic and semi-static signalling (e.g., SRS). The communication control module 163 is also configured for the overall handling of receipt of downlink communication from the RAN node 5-1. For example, where the intermediate / assisting node 5-2 is a UE 3 (or at least operates like a UE in its communication with the RAN node 5-1) this downlink communication may be via associated downlink channels (e.g., of DCI via a physical downlink control channel (PDCCH) and / or a physical downlink shared channel (PDSCH)) including both dynamic and semi-persistent scheduling (e.g., SPS). It will, nevertheless, be appreciated that where the assisting node 5-2 is a device other than a UE 3 (e.g., an IAB or dedicated relay) then the communication control module 163 will be configured to communicate with the RAN node 5-1 using an appropriate corresponding signalling protocol for doing so.

[0316] The communication control module 163 is also responsible for appropriate ambient IoT related communication including, for example, reception of modulated backscattered communication from an ambient IoT device (where applicable) and / or downlink communication of an unmodulated carrier signal in accordance with ambient IoT (where applicable).

[0317] It will be appreciated that the communication control module 163 may include a number of sub-modules ('layers' or 'entities') to support specific functionalities. By way of example only the communication control module 163 may include sub-modules corresponding to the layers of a conventional protocol stack (PHY, MAC, RRC, RLC, PDCP etc.). Moreover, the communication control module 163 may include, sub-modules corresponding to the layers of a dedicated ambient IoT device protocol stack for controlling functions associated with those layers.

[0318] The communication control module 163 is configured, in particular, to control the assisting node's communication, in accordance with any of the methods described herein.

[0319] <Modifications and Alternatives> 　　Detailed examples been described above. As those skilled in the art will appreciate, a number of modifications and alternatives can be made to the above examples whilst still benefiting from the enhancements embodied therein.

[0320] It will be appreciated that description of features of and actions performed by a RAN node (or a RAN operating as an A-IoT device reader), apply equally to distributed type RAN nodes as to non-distributed type RAN nodes.

[0321] It will also be appreciated that whilst information elements having specific names may have been described, differently named information elements but having a similar purpose may be used.

[0322] In the above description the UE, A-IoT device, intermediate / assisting node, and the RAN node are described for ease of understanding as having a number of discrete functional components or modules. Whilst these modules may be provided in this way for certain applications, for example where an existing system has been modified to implement the disclosed enhancements, in other applications, for example in systems designed with the inventive features in mind from the outset, these modules may be built into the overall operating system or code and so these modules may not be discernible as discrete entities.

[0323] In the above examples, a number of software modules were described. As those skilled in the art will appreciate, the software modules may be provided in compiled or un-compiled form and may be supplied to the UE or base station as a signal over a computer network, or on a recording medium. Further, the functionality performed by part, or all, of this software may be performed using one or more dedicated hardware circuits. However, the use of software modules is preferred as it facilitates the updating of the UE or the base station in order to update their functionalities.

[0324] Each controller may comprise any suitable form of processing circuitry including (but not limited to), for example: one or more hardware implemented computer processors; microprocessors; central processing units (CPUs); arithmetic logic units (ALUs); input / output (IO) circuits; internal memories / caches (program and / or data); processing registers; communication buses (e.g. control, data and / or address buses); direct memory access (DMA) functions; hardware or software implemented counters, pointers and / or timers; and / or the like. Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

[0325] The User Equipment (or "UE," "mobile station," "mobile device" or "wireless device") in the present disclosure is an entity connected to a network via a wireless interface.

[0326] It should be noted that the present disclosure is not limited to a dedicated communication device and can be applied to any device having a communication function as explained in the following paragraphs.

[0327] The terms "User Equipment" or "UE" (as the term is used by 3GPP), "mobile station", "mobile device", and "wireless device" are generally intended to be synonymous with one another, and include standalone mobile stations, such as terminals, cell phones, smart phones, tablets, cellular IoT devices, IoT devices, and machinery. It will be appreciated that the terms "mobile station" and "mobile device" also encompass devices that remain stationary for an extended period of time.

[0328] A UE may, for example, be an item of equipment for production or manufacture and / or an item of energy related machinery (for example equipment or machinery such as: boilers; engines; turbines; solar panels; wind turbines; hydroelectric generators; thermal power generators; nuclear electricity generators; batteries; nuclear systems and / or associated equipment; heavy electrical machinery; pumps including vacuum pumps; compressors; fans; blowers; oil hydraulic equipment; pneumatic equipment; metal working machinery; manipulators; robots and / or their application systems; tools; moulds or dies; rolls; conveying equipment; elevating equipment; materials handling equipment; textile machinery; sewing machines; printing and / or related machinery; paper converting machinery; chemical machinery; mining and / or construction machinery and / or related equipment; machinery and / or implements for agriculture, forestry and / or fisheries; safety and / or environment preservation equipment; tractors; precision bearings; chains; gears; power transmission equipment; lubricating equipment; valves; pipe fittings; and / or application systems for any of the previously mentioned equipment or machinery etc.).

[0329] A UE may, for example, be an item of transport equipment (for example transport equipment such as: rolling stocks; motor vehicles; motorcycles; bicycles; trains; buses; carts; rickshaws; ships and other watercraft; aircraft; rockets; satellites; drones; balloons etc.).

[0330] A UE may, for example, be an item of information and communication equipment (for example information and communication equipment such as: electronic computer and related equipment; communication and related equipment; electronic components etc.).

[0331] A UE may, for example, be a refrigerating machine, a refrigerating machine applied product, an item of trade and / or service industry equipment, a vending machine, an automatic service machine, an office machine or equipment, a consumer electronic and electronic appliance (for example a consumer electronic appliance such as: audio equipment; video equipment; a loud speaker; a radio; a television; a microwave oven; a rice cooker; a coffee machine; a dishwasher; a washing machine; a dryer; an electronic fan or related appliance; a cleaner etc.).

[0332] A UE may, for example, be an electrical application system or equipment (for example an electrical application system or equipment such as: an x-ray system; a particle accelerator; radio isotope equipment; sonic equipment; electromagnetic application equipment; electronic power application equipment etc.).

[0333] A UE may, for example, be an electronic lamp, a luminaire, a measuring instrument, an analyser, a tester, or a surveying or sensing instrument (for example a surveying or sensing instrument such as: a smoke alarm; a human alarm sensor; a motion sensor; a wireless tag etc.), a watch or clock, a laboratory instrument, optical apparatus, medical equipment and / or system, a weapon, an item of cutlery, a hand tool, or the like. A UE may, for example, be a wireless-equipped personal digital assistant or related equipment (such as a wireless card or module designed for attachment to or for insertion into another electronic device (for example a personal computer, electrical measuring machine)).

[0334] A UE may be a device or a part of a system that provides applications, services, and solutions described below, as to "internet of things (IoT)," using a variety of wired and / or wireless communication technologies.

[0335] Internet of Things devices (or "things") may be equipped with appropriate electronics, software, sensors, network connectivity, and / or the like, which enable these devices to collect and exchange data with each other and with other communication devices. IoT devices may comprise automated equipment that follow software instructions stored in an internal memory. IoT devices may operate without requiring human supervision or interaction. IoT devices might also remain stationary and / or inactive for an extended period of time. IoT devices may be implemented as a part of a (generally) stationary apparatus. IoT devices may also be embedded in non-stationary apparatus (e.g., vehicles) or attached to animals or persons to be monitored / tracked.

[0336] It will be appreciated that IoT technology can be implemented on any communication devices that can connect to a communication system for sending / receiving data, regardless of whether such communication devices are controlled by human input or software instructions stored in memory.

[0337] It will be appreciated that IoT devices are sometimes also referred to as Machine-Type Communication (MTC) devices or Machine-to-Machine (M2M) communication devices. It will be appreciated that a UE may support one or more IoT or MTC applications. Some examples of MTC applications are listed in the following table. This list is not exhaustive and is intended to be indicative of some examples of machine type communication applications.

[0338] Further, the above-described UE categories are merely examples of applications of the technical ideas and exemplary examples described in the present document. Needless to say, these technical ideas and examples are not limited to the above-described UE and various modifications can be made thereto.

[0339] Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

[0340] For example, the whole or part of the exemplary embodiments disclosed above can be described as, but not limited to, the following supplementary notes. 　　(Supplementary note 1) 　　A method performed by a reader device, the method comprising: 　　transmitting, to a mobile device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled. 　　(Supplementary note 2) 　　The method according to supplementary note 1, wherein 　　the information is transmitted in at least one of: 　　　　layer 1 (L1) control information, 　　　　a medium access control (MAC) control element (CE), or 　　　　a higher layer signalling. 　　(Supplementary note 3) 　　The method according to supplementary note 1 or 2, wherein 　　the message includes at least one of: 　　　　information indicating an end of a current task / communication for the mobile device, 　　　　information indicating a periodicity indicating a next communication / paging, or 　　　　information indicating an offset for updating the periodicity indicating a next communication / paging. 　　(Supplementary note 4) 　　The method according to supplementary note 3, wherein 　　in a case where the message includes the information indicating the end timing of the current task / communication for the mobile device, and the information indicating whether the sleep state of the mobile device is enabled or disabled indicates that the sleep state of the mobile device is disabled, the message causes the mobile device to move to an off state of the mobile device. 　　(Supplementary note 5) 　　The method according to supplementary note 3 or 4, wherein 　　in a case where the message includes the information indicating the end timing of the current task / communication for the mobile device, and the information indicating whether the sleep state of the mobile device is enabled or disabled indicates that the sleep state of the mobile device is enabled, the message causes the mobile device to move to the sleep state of the mobile device. 　　(Supplementary note 6) 　　The method according to any one of supplementary notes 3 to 5, wherein 　　in a case where the message includes the information indicating the offset for updating the periodicity indicating a next communication / paging, the message causes the mobile device to calculate a periodicity indicating a next communication / paging to move the mobile device to an on state of the mobile device from the sleep state of the mobile device. 　　(Supplementary note 7) 　　A method performed by a mobile device, the method comprising: 　　receiving, from a reader device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled; and 　　enabling or disabling the sleep state of the mobile device based on the information. 　　(Supplementary note 8) 　　A reader device comprising: 　　means for transmitting, to a mobile device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled. 　　(Supplementary note 9) 　　A mobile device comprising: 　　means for receiving, from a reader device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled; and 　　means for enabling or disabling the sleep state of the mobile device based on the information.

[0341] This application is based upon and claims the benefit of priority from Great Britain Patent Application No. 2414569.0, filed on October 3, 2024, the disclosure of which is incorporated herein in its entirety by reference.

[0342] 1 COMMUNICATION SYSTEM 3 USER EQUIPMENT 5 BASE STATION 7 CORE NETWORK 9 CELL 10 CONTROL PLANE FUNCTIONS 11 USER PLANE FUNCTIONS 21 EXTERNAL DATA NETWORK 31 TRANSCEIVER CIRCUIT 33 ANTENNA 35 USER INTERFACE 37 CONTROLLER 39 MEMORY 41 OPERATING SYSTEM 43 COMMUNICATIONS CONTROL MODULE 331 TRANSCEIVER CIRCUIT 331-1 ENERGY HARVESTING CIRCUITRY 331-2 MODULATION CIRCUITRY 331-3 SIGNAL AMPLIFIER 332 DATA SOURCE 333 ANTENNA 335 USER INTERFACE 337 CONTROLLER 338 PROCESSING CIRCUITRY 339 MEMORY 341 OPERATING SYSTEM 343 COMMUNICATIONS CONTROL MODULE 345 DATA BUFFER 51 TRANSCEIVER CIRCUIT 53 ANTENNA 55 CORE NETWORK INTERFACE 57 CONTROLLER 59 MEMORY 61 OPERATING SYSTEM 63 COMMUNICATIONS CONTROL MODULE 151 TRANSCEIVER CIRCUIT 153 ANTENNA 155 RAN INTERFACE 157 CONTROLLER 159 MEMORY 161 OPERATING SYSTEM 163 COMMUNICATIONS CONTROL MODULE

Claims

1. A method performed by a reader device, the method comprising: 　　transmitting, to a mobile device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled.

2. The method according to claim 1, wherein 　　the information is transmitted in at least one of: 　　　　layer 1 (L1) control information, 　　　　a medium access control (MAC) control element (CE), or 　　　　a higher layer signalling.

3. The method according to claim 1 or 2, wherein 　　the message includes at least one of: 　　　　information indicating an end of a current task / communication for the mobile device, 　　　　information indicating a periodicity indicating a next communication / paging, or 　　　　information indicating an offset for updating the periodicity indicating a next communication / paging.

4. The method according to claim 3, wherein 　　in a case where the message includes the information indicating the end timing of the current task / communication for the mobile device, and the information indicating whether the sleep state of the mobile device is enabled or disabled indicates that the sleep state of the mobile device is disabled, the message causes the mobile device to move to an off state of the mobile device.

5. The method according to claim 3 or 4, wherein 　　in a case where the message includes the information indicating the end timing of the current task / communication for the mobile device, and the information indicating whether the sleep state of the mobile device is enabled or disabled indicates that the sleep state of the mobile device is enabled, the message causes the mobile device to move to the sleep state of the mobile device.

6. The method according to any one of claims 3 to 5, wherein 　　in a case where the message includes the information indicating the offset for updating the periodicity indicating a next communication / paging, the message causes the mobile device to calculate a periodicity indicating a next communication / paging to move the mobile device to an on state of the mobile device from the sleep state of the mobile device.

7. A method performed by a mobile device, the method comprising: 　　receiving, from a reader device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled; and 　　enabling or disabling the sleep state of the mobile device based on the information.

8. A reader device comprising: 　　means for transmitting, to a mobile device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled.

9. A mobile device comprising: 　　means for receiving, from a reader device, a message including information indicating whether a sleep state of the mobile device is enabled or disabled; and 　　means for enabling or disabling the sleep state of the mobile device based on the information.

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