System and method of ambient IoT paging and random access supporting multiple readers

Abstract

A system and method for Ambient Internet of Things (A-IoT) paging and random access in New Radio (NR) systems are disclosed. The invention defines unified message structures for a reader-to-device paging message (msg0) and a device-to-reader response message (msg1) applicable to both Contention-Free Access (CFA) and Contention-Based Random Access (CBRA) procedures. The msg0 structure includes parameters such as paging identifier, message type identifier, transaction identifier, reader identifier, query type indicator, and time and frequency resource allocation information. The msg1 structure includes parameters such as a random identifier, message type identifier, data size indicator, device energy status indicator, data presence indicator, and upper-layer data. The invention further defines device behavior in multi-reader scenarios using transaction identifiers derived from a correlation identifier and reader identifier for Ambient IoT deployments in 5G Advanced and 6G systems.

Description

[0001] System and method of Ambient loT paging and random access supporting multiple readers

[0002] Field of the Invention

[0003] The present invention relates to wireless communication systems in New Radio (NR), and more particularly to a system and method for Ambient Internet of Things (loT) paging and random access supporting multiple readers, including unified message structures for contention-free access (CFA) and contention-based random access (CBRA) in 5G Advanced (5GA) and 6G.

[0004] Background of the Invention

[0005] Wireless communication systems have become integral to modern telecommunication services, supporting applications such as telephony, video streaming, data transmission, messaging, and broadcasting. These systems utilize multiple-access technologies to enable efficient communication by sharing resources such as bandwidth and transmit power among multiple users. Notable examples include Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Freguency Division Multiple Access (FDMA), Orthogonal Freguency Division Multiple Access (OFDMA), and Single-Carrier Freguency Division Multiple Access (SC-FDMA).

[0006] The advent of 5G New Radio (NR), developed by the Third Generation Partnership Project (3GPP), has significantly enhanced wireless communication capabilities by improving spectral efficiency, reducing costs, and enabling better service integration. 5G NR introduces key advancements such as beamforming, massive MIMO, and dynamic bandwidth part (BWP) management, facilitating a range of applications including enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low latency communications (URLLC). These enhancements aim to meet growing demands for low-latency, high-reliability, and scalable connectivity, particularly for emerging loT applications.

[0007] As wireless networks evolve to 5G Advanced (5GA) and 6G, the need for efficient resource allocation and energy management has become increasingly critical, particularly for low-power, battery-less loT devices. Ambient Internet of Things (A-loT) technologies have emerged to support battery-less or energy-constrained devices operating within New Radio (NR) systems, enabling devices to communicate by harvesting energy from surrounding radio frequency (RF) signals instead of relying on traditional battery power. Backscatter communication (BSC) is one such technique that allows severely resource-constrained devices to reflect and modulate ambient signals for data transmission.

[0008] Despite advancements in backscatter and ambient loT technologies, existing implementations face limitations such as high costs, short transmission ranges, and inefficient resource allocation. Current frameworks relying on technologies like WiFi, Bluetooth, and Zigbee offer limited coverage, requiring a dense deployment of nodes that increases overall energy consumption. Although low-power wide-area networks (LPWAN) provide extended communication range, they still depend on periodic battery replacements, adding maintenance overhead.

[0009] Managing communication in large-scale ambient loT deployments introduces additional challenges. Paging mechanisms, which notify devices of incoming data or trigger communication, can be power-intensive for energy-constrained loT devices. Frequent paging transmissions drain available energy, while ineffective paging strategies may result in delayed device wake-up, impacting network performance. Similarly, random access procedures, which allow loT devices to request network resources, can suffer from congestion and collisions when large numbers of devices attempt simultaneous access. These challenges are exacerbated when multiple readers or base stations attempt to communicate with the same device, leading to interference and inefficient resource utilization.In certain deployment scenarios, a plurality of base stations or readers may operate within overlapping coverage areas, such that an Ambient Internet of Things (A-loT) device located within a cell edge region may receive downlink paging messages from more than one reader. In such multi-reader environments, existing communication frameworks do not clearly define the operational behavior of the device with respect to selectively responding to paging messages, differentiating between identical or different service requests, and preventing redundant or repeated transmissions that may lead to resource inefficiency.

[0010] 3GPP Technical Report (TR) 38.769 discloses various paging scenarios wherein a paging message (msgO) is transmitted from a reader to a single device, multiple individual devices, (iii) a group of devices, or (iv) all devices within a coverage area. The random-access triggering mechanism associated with such paging message may be implemented using either contention-free access (CFA) or contention-based random access (CBRA). However, TR 38.769 does not define a unified message structure applicable to both the downlink paging message (msgO) and the corresponding uplink response message (msg1) across both CFA and CBRA procedures. Furthermore, the existing framework does not specify device decision logic or behaviour in scenarios involving multiple readers transmitting paging messages to the same A-loT device.

[0011] Despite advancements in wireless communication, current paging and random-access mechanisms for Ambient loT systems remain inefficient, particularly for low power devices in 5GA and 6G networks. The absence of a unified message structure for both downlink paging message (msgO) and uplink response message (msg1), applicable to both CFA and CBRA procedures, complicates large-scale deployment and multi-reader coordination. Therefore, there is a critical need for an optimized paging and random-access framework that enhances resource allocation, supports multiple readers, and minimizes energy consumption for Ambient loT devices in large-scale deployments.Objective of the Invention

[0012] The principal objective of the present invention is to provide a system and method for Ambient Internet of Things (loT) paging and random access supporting multiple readers, configured to enhance connectivity, reduce contention, and improve resource allocation efficiency in 5G Advanced (5GA) and 6G New Radio (NR) systems.

[0013] Another objective of the present invention is to provide a unified message structure for a downlink paging message (msgO) and a corresponding uplink response message (msg1) applicable to both Contention-free access (CFA) and Contention-Based Random Access (CBRA) procedures.

[0014] Another objective of the present invention is to define device operational behaviour in multi-reader scenarios, including selective response, transaction differentiation, and avoidance of redundant transmissions in overlapping coverage areas.

[0015] Another objective of the present invention is to enable an ambient loT device to distinguish between paging messages received from different readers by utilizing a transaction identifier associated with a reader identifier, thereby improving coordination and reducing interference.

[0016] Another objective of the present invention is to provide a time-domain and frequency-domain resource indication mechanism within the paging message, including contention-free and contention-based resource differentiation, to support scalable deployment of ambient loT devices.

[0017] Another objective of the present invention is to provide a mechanism for generating a transaction identifier using either a reader identifier and a correlation identifier received from a core network, or a derived identifier generated using a sequence-based or bitwise operation, thereby enabling unique identification of transactions across multiple readers.

[0018] A further objective of this invention is to enhance the performance of massive machine-type communications (mMTC) by optimizing randomaccess procedures, ensuring low-latency responses, and enabling seamless integration with 5G / 6G infrastructure.

[0019] Summary of the Invention

[0020] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0021] The present invention relates to a system, method, and device for ambient Internet of Things (loT) paging and random access in New Radio (NR) systems, particularly in 5G Advanced (5GA) and 6G massive Machine Type Communications (mMTC) deployments. The invention addresses Layer 1 and Layer 2 procedures between one or more readers and a plurality of A-loT devices, including battery-less or energy-constrained devices, and defines unified message structures and device behavior mechanisms applicable to multi-reader environments.

[0022] In one aspect, a reader is configured to transmit a downlink paging message (msgO) to one or more A-loT devices. The msgO follows a unified message structure applicable to multiple paging scenarios, including paging of a single device, multiple devices, a group of devices, or all devices within a coverage area. The unified msgO structure is applicable to both Contention-Free Access (CFA) and Contention-Based Random Access (CBRA) procedures. The msgO may comprise one or more of: a paging identifier, a message type identifier, a transaction identifier, a reader identifier, a query type indicator, and time-domain and frequency-domain resource allocation information. The msgO may further include an indication of the random-access type and optionally a CBRA resource start index distinguishing resources allocated for CFA and CBRA transmissions.

[0023] In another aspect, at least one A-loT device transmits an uplink response message (msg1) in response to the msgO. The msg1 follows aunified structure applicable to both CFAand CBRA procedures. The unified msg1 structure may include one or more of: a random identifier generated from a device identifier and device type, a message type identifier, a data size indicator, a device energy status indicator, a data presence indicator, and upper-layer data. In a two-step CFA procedure, upper-layer data may be transmitted in msg1, whereas in a four-step CBRA procedure, the msg1 may indicate information associated with subsequent transmission of upperlayer data.

[0024] In a further aspect, the invention defines operational behavior of an A-loT device in multi-reader scenarios in which the device may receive paging messages from multiple readers operating within overlapping coverage areas. The device may compare a transaction identifier included in a received msgO with a stored transaction identifier and determine whether to respond based on whether the transaction identifier corresponds to an ongoing or previously completed transaction. The device may selectively discard or respond to paging messages based on the transaction identifier and reader identifier, thereby enabling controlled operation in multireader environments.

[0025] In another aspect, a transaction identifier is generated based on a correlation identifier received from a core network and a reader identifier. The transaction identifier may be formed by transmitting both identifiers or by generating a derived identifier using a Gold sequence, an XOR operation, or a bit replacement operation between the correlation identifier and the reader identifier. The transaction identifier enables differentiation of transactions associated with different readers or services.

[0026] Accordingly, the invention provides unified message structures for the downlink paging message (msgO) and the uplink response message (msg1 ), wherein the unified structures are applicable across multiple paging scenarios and to both Contention-Free Access (CFA) and Contention-Based Random Access (CBRA) procedures. The invention further establishes mechanisms for generation, and interpretation of transactionidentifiers derived from correlation identifiers and reader identifiers, thereby enabling differentiation of transactions in multi-reader environments. In addition, the invention specifies device-side decision logic for selectively responding to or discarding paging messages based on transaction identifiers and reader identifiers. By defining unified signaling structures and structured device behavior at Layer 1 and Layer 2 within NR systems, the invention provides a consistent framework for paging and random access in A-loT deployments involving multiple readers.

[0027] The foregoing general description of the illustrative embodiments and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure and are not restrictive.

[0028] Brief description of the drawings

[0029] The figures described below depict various aspects of the system and methods disclosed herein. It should be understood that each figure depicts an embodiment of a particular aspect of the disclosed system and methods, and that each of the figures is intended to accord with a possible embodiment thereof. Further, wherever possible, the following description refers to the reference numerals included in the following figures, in which features depicted in multiple figures are designated with consistent reference numerals.

[0030] FIG. 1 illustrates a conventional communication system (100) depicting interactions between ambient loT devices and multiple readers, in accordance with a preferred embodiment of the present invention.

[0031] FIG. 2 shows two communication scenarios (200) between a reader and a device: a 2-step communication process and a 4-step communication process.

[0032] FIG. 2(A) depicts a 2-step communication process between a reader and device, according to one embodiment of the present invention.

[0033] FIG. 2(B) presents a 4-step communication process between a reader and device, in accordance with an embodiment of the invention.FIG. 3 illustrates a timing diagram (300) depicting the uplink (UL) and downlink (DL) message exchanges between a device and a reader, in accordance with a preferred embodiment of the present invention.

[0034] FIG. 4 presents a unified MsgO structure (400) applicable to both 2-step CFA and 4-step CBRA scenarios, in accordance with an embodiment of the present invention.

[0035] FIG. 5 depicts a unified Msg1 structure (500) applicable to both 2-step CFA and 4-step CBRA scenarios, in accordance with an embodiment of the invention.

[0036] FIG. 6 shows a scenario (600) where a device receives paging messages from multiple base stations (BSs) or readers, according to a preferred embodiment of the present invention.

[0037] FIG. 7 depicts the flowchart (700) depicting a method for unified paging and hybrid random access in a wireless communication network supporting multiple readers and ambient Internet of Things (A-loT) devices, in accordance with one embodiment of the present invention.

[0038] FIG. 8 illustrates a network node (800) configured to support unified paging and random-access procedures for Ambient Internet of Things (A-loT) devices in a multi-reader communication environment, in accordance with one embodiment of the present invention.

[0039] Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.

[0040] Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.Description of the invention

[0041] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

[0042] The terms and words used in the following description and claims are not limited to the bibliographical meanings but are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

[0043] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.

[0044] By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic is intended to provide.

[0045] Figures discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way that wouldlimit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system. The terms used to describe various embodiments are exemplary. It should be understood that these are provided to merely aid the understanding of the description, and that their use and definitions, in no way limit the scope of the invention. Terms first, second, and the like are used to differentiate between objects having the same terminology and are in no way intended to represent a chronological order, unless where explicitly stated otherwise. A set is defined as a non-empty set including at least one element.

[0046] Figure 1 illustrates a conventional communication system (100) designed for ambient loT paging and random access, supporting multiple readers. The communication system (100) comprises a plurality of ambient Internet of Things (loT) devices, a plurality of readers or base stations configured to communicate with the ambient loT devices, and a core network (CN) configured to coordinate communication between the readers and the ambient loT devices. The ambient loT devices are distributed across a designated deployment area, and the readers are deployed at different locations within the communication system to provide wireless connectivity to the ambient loT devices.

[0047] In the illustrated embodiment, the readers are deployed across multiple coverage regions within the communication system. Each reader is configured to provide wireless communication coverage within a corresponding region and to establish communication with one or more ambient loT devices located within that region. The ambient loT devices are illustrated as device elements distributed throughout the coverage regions served by the readers. The readers are illustrated as base station or antenna nodes configured to transmit wireless signals toward the ambient loT devices and receive response signals from the devices.

[0048] In one embodiment, the ambient loT devices may comprise batteryless devices or energy-constrained devices configured to operate usingultra-low power communication mechanisms. Such devices may be configured to transmit uplink information to the readers in response to received signals. The readers operate as network access nodes configured to transmit downlink paging or query signals toward the ambient loT devices and receive uplink responses from the devices. In certain embodiments, the readers may perform functions including device discovery, device inventory collection, paging procedures, and scheduling of communication resources associated with the ambient loT devices.

[0049] As further illustrated in FIG. 1, the communication system (100) includes multiple readers deployed across the network area such that the corresponding coverage regions may partially overlap. As a result, certain ambient loT devices located near boundaries of adjacent coverage regions may be capable of receiving wireless signals from more than one reader. In such multi-reader deployment scenarios, an ambient loT device positioned near the boundary of two or more coverage regions may receive paging or query signals transmitted from multiple readers.

[0050] In one embodiment, the readers are further connected to the core network (CN) through communication links represented by dashed arrows in the figure. The core network may include backend servers or network control entities configured to coordinate service transactions and communication procedures associated with the ambient loT devices. The core network may generate service requests or queries directed toward one or more ambient loT devices, and such requests may be forwarded to the corresponding readers to initiate communication procedures with the ambient loT devices located within their coverage regions.

[0051] In certain embodiments, communication between the readers and ambient loT devices may include downlink transmissions from the readers to the devices and uplink transmissions from the devices to the readers. The downlink transmissions may include paging messages or query signals intended to trigger responses from the ambient loT devices, while the uplinktransmissions may include response signals or device-related information transmitted by the devices toward the readers.

[0052] The communication system in FIG. 1 therefore represents a multireader ambient loT deployment scenario in which a large number of ambient loT devices are distributed across a network area served by multiple readers and coordinated through the core network. In such deployment environments, ambient loT devices located near overlapping coverage regions may receive paging signals from multiple readers, which may lead to challenges related to device response behavior, resource allocation, and communication efficiency.

[0053] Accordingly, the communication system illustrated in FIG. 1 provides a representative operational environment for ambient loT communication involving multiple readers and a large population of ambient loT devices. The subsequent embodiments of the present invention address these challenges by introducing mechanisms including unified paging message structures, unified random access response structures, and device behavior rules for handling communication scenarios involving multiple readers.

[0054] FIG. 2 illustrates two distinct communication scenarios between a reader (base station) and an Ambient loT (A-loT) device (200), namely the 2-step communication process (FIG. 2a) and the 4-step communication process (FIG. 2b). These communication processes are integral to the random-access mechanism used in 5GA and 6G massive Machine Type Communications (mMTC), facilitating efficient and reliable device-reader interactions. The choice between these two processes depends on network conditions, device capabilities, and the type of random-access mechanism implemented.

[0055] FIG. 2 shows two communication scenarios (200) between a reader and a device: a 2-step communication process and a 4-step communication process. The communication scenarios 200 illustrate a random access communication procedure between a reader and an ambient Internet of Things (A-loT) device.In one embodiment, the reader initiates a communication procedure by transmitting a paging message (MsgO) to one or more ambient loT devices. The paging message acts as a trigger for device response and initiates a random-access procedure through which the devices may transmit uplink information toward the reader.

[0056] In certain embodiments, the random-access procedure may operate using either contention-free access (CFA) or contention-based random access (CBRA) depending on whether the responding device is known to the reader or whether multiple devices may attempt to access the network simultaneously.

[0057] FIG. 2(A) depicts a 2-step communication process between a reader and a device, which may be implemented in contention-free access (CFA) scenarios. In one embodiment, the reader may possess prior knowledge of the identity of the device expected to respond to a paging request. In such scenarios, the reader may allocate dedicated communication resources to the device prior to the transmission of the device response. Because the responding device and associated communication resources are known in advance, the communication transaction may be completed with a reduced number of signaling exchanges.

[0058] Accordingly, the 2-step communication procedure enables efficient device-reader communication with minimal signaling overhead, reduced latency, and lower power consumption, which is particularly beneficial for battery-less or energy-constrained ambient loT devices.

[0059] In Step A, occurring at time TO, the reader transmits a downlink paging message (MsgO) toward the device. In one embodiment, MsgO may serve as an inventory command, paging query, or service request transmitted from the reader to one or more devices. The paging message may include various control parameters that enable the device to interpret the request and determine the required response behavior.

[0060] In certain embodiments, MsgO may include fields such as paging identification information, reader identification information, transaction orservice identification, and scheduling information that specifies the resources allocated for the device to transmit its response. The scheduling information may include time-domain resource allocation, frequencydomain resource allocation, or a combination thereof. In an example embodiment, MsgO may also contain an identifier corresponding to a specific device or a set of devices that are expected to respond to the paging request.

[0061] In Step B, occurring at time T1, the device transmits an uplink response message (Msg1) toward the reader. In one embodiment, Msg1 may contain device-related information, such as a device identifier, device type, group identifier, or other information requested by the reader. Because the uplink resources may have already been allocated by the reader through MsgO, the device may directly transmit Msg1 without performing additional contention or scheduling procedures.

[0062] As a result, the communication procedure may be completed after the transmission of Msg1, thereby forming a two-message exchange process between the reader and the device. This simplified communication mechanism reduces signaling complexity and is particularly advantageous for large-scale ambient loT deployments involving energy-constrained devices.

[0063] FIG. 2(B) presents a 4-step communication process between a reader and a device, which may be used in contention-based random access (CBRA) scenarios.

[0064] In another embodiment, this procedure may be applied when the reader does not possess prior knowledge of the number or identity of devices that may respond to a paging request. For example, the reader may transmit a paging message directed toward multiple devices, a group of devices, or all devices located within the coverage area of the reader. In such cases, multiple devices may attempt to access the network simultaneously, and therefore additional signaling exchanges may be required to coordinate access and allocate communication resources.In Step A, occurring at time TO, the reader transmits a downlink paging message (MsgO) toward one or more devices. In one embodiment, MsgO may function as a query or inventory command that initiates the random-access procedure. Unlike the contention-free access procedure described in FIG. 2(A), MsgO in the contention-based procedure may not assign dedicated uplink resources to specific devices. Instead, MsgO may trigger multiple devices to initiate a random-access attempt.

[0065] In Step B, occurring at time T1, one or more devices transmit Msg1 toward the reader. In certain embodiments, Msg1 may include a randomly generated identifier (random ID) rather than the actual device identifier. The use of a randomly generated identifier enables multiple devices to attempt network access while reducing the probability of collisions between simultaneous transmissions. In an example embodiment, the random identifier may be generated using a predetermined randomization algorithm based on device-specific parameters.

[0066] In Step C, occurring at time T2, the reader transmits Msg2 toward the responding device. In one embodiment, Msg2 may serve as an acknowledgment message indicating that the random identifier transmitted by the device in Msg1 has been successfully received. In certain embodiments, Msg2 may further include scheduling information, such as time-domain resource allocation, frequency-domain resource allocation, or other resource assignment information that specifies the communication resources that the device may use for transmitting its full information in the next step.

[0067] In Step D, occurring at time T3, the device transmits Msg3 toward the reader using the allocated communication resources. In one embodiment, Msg3 may contain uplink data, including the actual device identifier, device type, device capability information, or other information requested by the reader. Subsequently, at time T4, the reader may transmit Msg4, which may serve as a final acknowledgment message. In certain embodiments, Msg4 may include an acknowledgment (ACK) indicatingsuccessful reception of Msg3 or a negative acknowledgment (NAK) indicating that the transmission was unsuccessful and that the device may need to retransmit the data.

[0068] The 4-step contention-based random-access procedure enables multiple devices to access the network in scenarios where the reader does not have prior knowledge of the responding devices. By incorporating random identifier-based contention and subsequent resource scheduling, the procedure enables efficient handling of multiple simultaneous access attempts and improves network scalability in large-scale ambient loT deployments.

[0069] Although the communication procedures illustrated in FIG. 2(A) and FIG. 2(B) enable communication between readers and ambient loT devices, certain limitations may arise in conventional implementations. In particular, ambient loT devices may not always have prior knowledge of whether the communication procedure will follow a 2-step contention-free access mechanism or a 4-step contention-based random-access mechanism. Differences in message structures and signaling procedures between these mechanisms may increase device processing complexity. In certain embodiments, such complexity may lead to increased power consumption, which is undesirable for battery-less or energy-constrained ambient loT devices.

[0070] Accordingly, the present invention proposes mechanisms that enable efficient operation of both communication procedures. In certain embodiments, the invention introduces unified message structures for paging message (MsgO) and device response message (Msg1) that are applicable to both contention-free access and contention-based randomaccess procedures. By enabling ambient loT devices to interpret paging signals and generate responses using a unified message format, the proposed approach reduces device complexity, improves communication efficiency, and supports large-scale ambient loT deployments involving multiple readers and a large number of devices.FIG. 3 illustrates a timing diagram (300) that represents the uplink (UL) and downlink (DL) message exchanges between Ambient Internet of Things (loT) devices and multiple readers in a 5GA and 6G massive Machine Type Communications (mMTC) network. The timing diagram 300 illustrates a slot-based communication mechanism between one or more readers and one or more ambient loT devices.

[0071] In one embodiment, communication between the reader and the devices is organized into communication slots, where each slot represents a defined time interval during which a sequence of downlink and uplink messages may be exchanged. A plurality of such communication slots may collectively form a transaction cycle or inventory cycle, which represents a communication period during which the reader performs device discovery or inventory operations from ambient loT devices located within its coverage area. In certain embodiments, the reader schedules communication with the devices on a slot-by-slot basis, thereby enabling efficient management of device responses in large-scale deployments.

[0072] In accordance with 3GPP TR 38.769, Ambient loT communication often involves multiple communication slots, as all devices may not be scheduled by the base station (BS) in a single slot. The reader can trigger four different types of paging messages to initiate communication with devices:

[0073] • Case-1 : Reader sends a paging query to a single device.

[0074] • Case-2: Reader sends a paging query to multiple devices individually.

[0075] • Case-3: Reader sends a paging query to a group of devices.

[0076] • Case-4: Reader sends a paging query to all devices within its coverage area.

[0077] As illustrated in the upper portion of FIG. 3, a single communication slot is expanded to show the detailed sequence of message exchanges between the reader and the device. In one embodiment, the reader transmits a paging message (MsgO) at time TO toward the device through adownlink physical channel referred to as the physical reader-to-device channel (PRDCH). The paging message may function as an inventory command or query signal that triggers a response from the device.

[0078] Upon receiving the paging message, the device may transmit an uplink response message (Msg1) at time T1 through an uplink physical channel referred to as the physical device-to-reader channel (PDRCH). In certain embodiments, Msg1 may include either a device identifier or a randomly generated identifier depending on whether the communication procedure follows a contention-free access mechanism or a contentionbased random-access mechanism.

[0079] Following the reception of Msg1, the reader may transmit Msg2 at time T2 through the PRDCH channel. In one embodiment, Msg2 may indicate acknowledgment of the received Msg1 and may further include scheduling information for subsequent transmissions. Subsequently, the device may transmit Msg3 at time T3 through the PDRCH channel using the resources assigned by the reader. Msg3 may include device-related information such as a device identifier, device type, or other data requested by the reader. In certain embodiments, the reader may transmit Msg4 at time T4, which may indicate an acknowledgment (ACK) or negative acknowledgment (NAK) corresponding to the received data transmission.

[0080] In one embodiment, the transaction or inventory cycle may include multiple communication slots because all ambient loT devices located within the reader coverage area may not be able to transmit responses within a single slot. Therefore, the reader may allocate several communication slots within a transaction cycle to enable different devices to respond at different times. Devices receiving the paging message may respond during different communication slots, thereby distributing device responses across multiple slots within the transaction cycle and reducing the probability of simultaneous transmissions and communication collisions.

[0081] The timing diagram also depicts communication sequences associated with multiple readers, such as Reader 1 and Reader 2, operatingwithin the same network environment. In certain embodiments, each reader may execute its own transaction or inventory cycle consisting of multiple communication slots. Because the readers may operate independently, the transaction cycles associated with different readers may occur simultaneously or with partial time offsets. Consequently, ambient loT devices located within overlapping coverage areas may receive paging messages from more than one reader during overlapping communication periods. In the timelines corresponding to Reader 1 and Reader 2, slot boundaries are illustrated using timing markers such as TO, T1 and T1, which represent sequential time intervals corresponding to the start of different communication slots within a transaction cycle.

[0082] In another embodiment, such overlapping reader operations may result in multi-reader paging scenarios, where a device receives paging requests from multiple readers associated with different service requests or transaction identifiers. In such scenarios, the device may determine whether to respond to a particular reader based on parameters included in the paging message, such as reader identification information or transaction identification information.

[0083] The multi-reader communication environment illustrated in FIG. 3 therefore forms the basis for the device behavior mechanisms described in subsequent sections of the present disclosure, particularly with respect to device response handling in multi-reader paging scenarios.

[0084] Accordingly, the timing diagram illustrated in FIG. 3 demonstrates how slot-based communication, transaction cycles, and multi-reader operation enable scalable and efficient communication in large-scale ambient loT deployments. The diagram further illustrates the timing relationships between downlink paging transmissions and uplink device responses, enabling coordinated random-access procedures across multiple communication slots and across multiple readers operating within the same network environment.Figure 4 illustrates a unified message structure (msgO) for both 2-step contention-free access (CFA) and 4-step contention-based random access (CBRA) communication in an Ambient loT (A-loT) system. This unified structure is designed to optimize the paging and random-access process, enabling efficient transmission and reception of messages between readers (base stations) and devices. By supporting both CFA and CBRA, the proposed message format ensures minimal signaling overhead, enhanced device coordination, and improved network efficiency, particularly in massive Machine Type Communications (mMTC) for 5G-Advanced (5GA) and 6G networks.

[0085] The msgO structure is a Reader-to-Device (R2D) message, transmitted over the Physical Random Access Downlink Channel (PRDCH). It consists of multiple components arranged in a hierarchical flow, ensuring seamless communication between devices and readers. The data portion of msgO contains R2D information bits extracted from Layer 2, which undergo several processing steps to ensure robust transmission. First, the data is appended with a cyclic redundancy check (CRC) for error detection, followed by line coding to enhance reliability. The encoded data is then modulated using On-Off Keying (OOK-1 / OOK-4) combined with Orthogonal Frequency Division Multiplexing (OFDM), ensuring spectral efficiency and interference resilience.

[0086] The msgO structure is composed of three primary components, which are processed in parallel before being assembled into the final PRDCH transmission format. The first component is the preamble sequence, generated by a preamble sequence generator triggered by an R2D synchronization signal. This preamble helps devices synchronize with the reader and detect the start of a new paging message. The second component is the processed data payload, which carries essential information for paging and random access. Finally, the postamble sequence, generated by a postamble sequence generator, marks the end of the message transmission. Additionally, start indicators and clockacquisition components ensure proper timing alignment, while an end-of-frame marker signals the conclusion of msgO.

[0087] The unified msgO structure is applicable to all four query types (Case-1 to Case-4) proposed in this invention, allowing the reader to communicate efficiently with devices. The PRDCH data part contains the R2D information bits from Layer 2, and the reader uses msgO to convey the query type to the device while allocating the appropriate time and frequency domain resources. The field parameters of msgO are structured as follows:

[0088] • Paging ID: Paging ID contains the information to convey to the device whether the received message corresponds to the first paging message ora repeated paging message of the same communication slot of the same transaction cycle.

[0089] • Message type: Message type can be conveyed implicitly or explicitly by indicating an ID value as part of each message signal that should indicate the type of the message signal. Like, msgO should contain an ID which indicates that this is the initial DL broadcast signal transmitted from the reader to initiate the inventory command procedure.

[0090] • Transaction / service ID: The A-loT communication involves multiple communication slots, as shown in Fig. 3, as all the devices may not be scheduled by the reader (BS) at one slot. Once a device completes the inventory process, it should not respond to the next consecutive slots within that inventory process to free up the resources for the other devices. Therefore, msgO signal should contain a transaction ID or inventory cycle ID. Devices that receive ACK signal in msg4 will decode every subsequent msgO signal transmitted form the reader (BS) to check the inventory cycle ID. If the inventory cycle ID is same as the previous ID, it will not respond to that msgO signal by transmitting msg1 signal. The device also may carry the transaction / service ID or an associate ID in the UL messagesignals. Upon matching the ID at the reader side, the reader will schedule the device.

[0091] • Reader ID: BS / reader ID is a unique ID, generated at the BS that can be transmitted at every message signal DL to indicate the device about the source of the received DL signal. If a device at the cell edge already involved in a communication process with one BS, it will discard the DL message signals received from other BSs. The device also may carry the BS ID or an associate ID in the UL message signals. Upon matching the BS ID, it will schedule the device. The BS ID can also be used at the device to avoid responding to any false reader.

[0092] • Query type: MsgO can carry 2 bits to convey the different query types of case-1 , case-2, case-3, or case-4 to the devices.

[0093] • Alternate 1: CFA / CBRA: MsgO can carry a 1 -bit indicator to convey the device if it is CFA or CBRA.

[0094] • Alternate 2: CBRA resource start Index: In case of a msgO carrying msg1 scheduling for both CFA and CBRA based random access, this index indicates the start of resource index to be used for CBRA based msg1 transmission. In the list of device random IDs in msgO, whose index value is greater than this start index will use CBRA based random access and devices whose index in the random ID list is less than the start index will map to individual resource for CFA random access.

[0095] • Upper layer data: This field carries device-related information depending on the query type. In case the reader sends a query to one device (case-1) or multiple specific devices (case-2), the upper layer data may include identifiers associated with the targeted devices, such as device random identifiers or device-related identifiers. In case the reader sends a query to a group of devices (case-3), the upper layer data may contain a group identifier. In casethe reader sends a query to all devices within the coverage area (case-4), this field may be empty or contain a default value.

[0096] In certain embodiments, the random-access type may be indicated explicitly through a CFA / CBRA indicator field included in msgO. In other embodiments, the device may implicitly determine the access type based on the content of the upper layer data or the presence of dedicated device identifiers in the paging list. For example, if msgO contains identifiers of specific devices with dedicated resource assignments, the device may interpret the procedure as contention-free access (CFA). If msgO indicates shared resources for multiple devices or does not contain specific device identifiers, the device may interpret the procedure as contention-based random access (CBRA).

[0097] The device random ID can be generated at the reader side from the actual device ID and device type using the same method that the device uses to generate its random ID. If the device generated device random ID matches with the reader generated device random ID, the device responds to the query message.

[0098] • Time domain resources:

[0099] Option 1: Time Resource Indication (T1 ... TX): This field contains the time domain resources either dedicatedly allocated to the device(s) for case-1 and case-2 or available time domain resources for the devices to send msg1 , where Ti is the time slot index.

[0100] Option 2: Total Time slots for sending msg1. This indicates the total number of time slots that are allocated for sending msg1 for the devices being paged in this msgO. The start of time resources for sending msg1 is from the end of msgO time + T_processing (optional) where T_processing is the time needed by the device to process the received msgO and prepare the msg1 for transmission.

[0101] The device can calculate the start of a time slot time slot as (T_msgO_end + timeSlotlndex*timeSlotDuration), wheretimeSlotDuration is the duration of an individual time slot (preconfigured and / or a fixed value),

[0102] timeSlotlndex is the index of the time slot for this device within the total time slots allocated in msgO.

[0103] • Frequency domain resources

[0104] Option 1: Frequency Resource Indication (F1 ... FY): This field contains the frequency domain resources either dedicatedly allocated to the device(s) for case-1 and case-2 or available frequency domain resources for the devices to send msg1 , where Fi is the frequency slot index.

[0105] Option 2: Total number of frequency resources for sending msg1. This indicates the total number of frequency resources that are allocated for sending msg1 for the devices being paged in this msgO.

[0106] For example, consider a sample msgO carrying paging for Device 0, Device 1, Device 2, and Device 3 in Case-2, while also including an indication for Case-4, where all devices in the coverage are paged. In this scenario, msgO assigns three time slots and three frequency resources per time slot for msg1 transmission. Additionally, the CBRA start index is set to 4, meaning:

[0107] • Devices DO, D1, D2, and D3 are mapped to RO, R1, R2, and R3, respectively, for CFA-based access.

[0108] • Resources R4 to R8 are allocated for CBRA-based access, allowing other devices in the reader's coverage area to respond.

[0109] The msgO structure ensures robust multi-reader coordination, allowing devices to distinguish between paging requests from different readers (base stations) while optimizing time and frequency allocation for efficient access. This approach is highly scalable, supports massive loT connectivity, and minimizes power consumption, making it ideal for batteryless loT applications.By assembling these components into the final PRDCH message format, msgO enables seamless paging and random-access communication. The final PRDCH structure consists of four sequential sections: preamble, data payload, postamble, and optional padding (if required). The preamble synchronizes the device, the data payload carries the core information, the postamble ensures message integrity, and padding is used for maintaining a fixed-length format when necessary.

[0110] Figure 5 illustrates a unified message structure (msg1 ) for device-to-reader (D2R) communication, applicable to both 2-step contention-free access (CFA) and 4-step contention-based random access (CBRA) protocols. This structure is designed to standardize how loT devices respond to paging messages (msgO) received from the reader (base station), ensuring efficient transmission, structured resource allocation, and minimal signaling overhead in an Ambient loT (A-loT) network. The msg1 message format follows a hierarchical processing flow, with multiple components arranged to optimize message integrity, synchronization, and power efficiency.

[0111] In one embodiment, at the top level, msg1 contains D2R (Device-to-Reader) information bits extracted from Layer 2 (L2) of the communication stack. These information bits are categorized into Control Information and Data Components, ensuring a clear separation of signaling information and device responses. The Control Information consists of several key fields, including Random ID, Message Type, Data Size, Device Energy Status, Data Presence Indicator, and Upper Layer Data. These fields define how the device interacts with the reader and whether the message is part of a 2-step CFA or a 4-step CBRA process.

[0112] The processing of msg1 follows three parallel paths, each contributing to different aspects of message formation. The left path represents the "Start Indicator" and "Clock Acquisition", which help the device establish timing synchronization with the reader. These signals are passed to a "Preamble Sequence Generator", which creates the preamblesection of msg1, ensuring the reader can correctly detect the beginning of the transmission. The center path processes the D2R information bits, passing them through CRC attachment (for error detection), Line Coding (for signal robustness), and Modulation (using OOK / BPSK schemes). This processed data forms the PRACH / PDRCH uplink data portion of msg1 , which carries the actual message payload. The right path contains the "End of Frame" signal, triggering the "Postamble Sequence Generator", which marks the completion of the msg1 transmission and allows the reader to determine the end of the uplink message.

[0113] These three processing paths converge to form the complete msg1 structure, which consists of four primary sections. The Preamble Section synchronizes the device’s transmission with the reader. The PDRCH Data Payload carries device response information, including random ID, upperlayer data, and transmission parameters. The Postamble Section signals the end of the message, ensuring proper frame alignment and avoiding transmission errors. Lastly, Padding is added when needed to maintain a fixed-length message structure, optimizing spectral efficiency in wireless communication.

[0114] The msg1 structure supports all four query types (Case-1 to Case-4), allowing devices to respond to different types of paging messages. The PDRCH data part contains the D2R information bits from Layer 2, and the device responds according to the query type specified in msgO. The key field parameters of msg1 are structured as follows:

[0115] • Random ID: Msg1 signal carries a random ID generated from the actual device ID and device type to send the response to msgO. • Message type: Message type can be conveyed implicitly or explicitly by indicating an ID value as part of each message signal that should indicate the type of the message signal. Like, msg1 should contain an ID which indicates this is the UL random access response to the reader from the device.• Data size: In 4-step CBRA process the data size is the size of upper layer data to be conveyed through msg3 in the 4-step process. In 2- step CFA process, data size is either the size of data present in the field “upper layer data” or it is ‘0’ conveys that there is no msg3. • Device energy status: Device may send the device energy status either implicitly or explicitly to the reader as a scheduling parameter.

[0116] • Data presence indicator: The data presence indicator specifies whether upper layer data is included in msg1. In a 2-step contention- free access (CFA) procedure, the data presence indicator is set to ‘T, indicating that the device transmits upper layer data in msg1. In a 4-step contention-based random access (CBRA) procedure, the data presence indicator is set to ‘O’, indicating that the device will transmit the upper layer data in a subsequent message (msg3). • Upper layer data: For 2-step CFA process, the device sends the upper layer data, which is the actual information consists of device ID, group ID, etc. through msg1 only. For 4-step CBRA process, the device sends the upper layer data through msg3. In that case, the upper layer data field in msg1 is empty or no data present in that field. The unified msg1 structure in FIG. 5 provides several key advantages for low-power, efficient, and scalable device-to-reader communication in 5G-Advanced and 6G mMTC networks.

[0117] The seamless integration of CFA and CBRA protocols allows devices to transmit responses efficiently, regardless of whether pre-assigned resources are available. By incorporating Data Presence Indicators, transaction-related identifiers, and Energy Status fields, msg1 enhances resource management and ensures devices transmit optimally based on power availability.

[0118] The CRC attachment process improves message reliability, reducing errors in UL transmissions, while the random ID mechanism allows devices to respond with minimal data, reducing signaling overhead in CBRA scenarios. The standardized structure supports massive loT deploymentsby accommodating individual, group, and broadcast paging requests (Case-1 to Case-4).

[0119] Additionally, the low-power modulation schemes (OOK / BPSK) minimize energy consumption, making this protocol highly suitable for battery-constrained A-loT devices. By ensuring a clear separation between control and data components, msg1 supports dynamic adaptation to network load, enabling large-scale communication while maintaining low latency.

[0120] Figure 6 illustrates a sequence diagram (600) depicting the interactions between multiple readers (R1 , R2, and R3) and an ambient loT device (D) over time. The message exchanges are represented along parallel timelines corresponding to each reader and the device. The diagram demonstrates how an Ambient Internet of Things (A-loT) device operates in a multi-reader communication environment where multiple readers may transmit paging requests to the device during overlapping communication intervals. In such environments, the device performs a decision process to determine whether a paging request should be responded to or ignored in order to avoid unnecessary contention and inefficient resource utilization.

[0121] The communication sequence begins at time TO when Reader 1 (R1 ) initiates an inventory process by transmitting a paging message MsgO to the device. Upon receiving MsgO, the device transmits Msg1 as a response to the reader. The communication continues according to the random-access procedure, where the reader transmits Msg2 at time T2, followed by the device transmitting Msg3 at time T3. Finally, Reader 1 transmits Msg4 at time T4, thereby completing the communication transaction between the reader and the device.

[0122] However, during the same time period, other readers may also attempt to initiate communication with the device. For example, Reader 2 (R2) may transmit another MsgO during the ongoing transaction between R1 and the device, and Reader 3 (R3) may also transmit an additional paging request. Because the device is already engaged in an activecommunication procedure with Reader 1, the device temporarily ignores or discards these additional paging requests until the current transaction is completed.

[0123] After the communication with Reader 1 is completed, the device transitions into an idle or listening mode, as illustrated at the bottom of the sequence diagram. During this mode, the device continues to monitor incoming paging messages transmitted by other readers. The device evaluates each received paging message in order to determine whether the device should respond to the request. This decision may depend on parameters such as transaction identifiers, service identifiers, and previously completed communication transactions. By performing this evaluation process, the device avoids redundant responses and prevents unnecessary collisions in the communication channel.

[0124] In multi-reader communication scenarios, it is possible that different readers may initiate inventory processes at slightly different time instants, resulting in overlapping paging messages. When such overlapping communication occurs, the device applies a set of decision rules to determine whether to respond to the paging message. These decision rules are based on factors including the identity of the reader that transmitted the request and the transaction or service identifier associated with the paging message.

[0125] In Case-1: Device receives the same service request from the same reader. In this scenario, the device has previously completed a communication transaction associated with a particular service request from a reader and subsequently enters an idle or listening mode. If the device later receives another paging request from the same reader corresponding to the same service request, the device compares the transaction identifier stored in its memory with the transaction identifier received in the paging message. If the identifiers are identical, the device determines that the paging message corresponds to a previously completed transaction. Accordingly, the device discards the request and refrains from transmittinga response message, thereby reducing unnecessary channel contention and conserving communication resources.

[0126] In another scenario Case-2: Device receives the same service request from a different reader, the device may receive a paging request associated with the same service but transmitted by a different reader. In this case, the device compares the transaction identifier stored from the previous transaction with the transaction identifier contained in the newly received paging message. If the identifiers are different, the device determines that the request corresponds to a separate communication transaction initiated by another reader. As a result, the device may respond to the paging message and initiate a new communication procedure with the second reader.

[0127] In some situations, case-3: Device receives a different service request from the same reader, the same reader may initiate another service request directed to the device after the previous transaction has been completed. In such cases, the device again compares the stored transaction identifier with the identifier contained in the new paging message. If the transaction identifiers differ, the device interprets the paging message as a new service request and may proceed to respond to the reader by initiating the appropriate random-access procedure.

[0128] In another scenario, Case-4: Device receives a different service request from a different reader, the device may receive a new service request from a different reader after completing the previous communication transaction. The device compares the transaction identifier stored in its memory with the identifier received in the new paging message. If the identifiers are different, the device determines that the paging message corresponds to a distinct service request from another reader and may respond to the request accordingly.

[0129] To support these decision mechanisms, the device utilizes transaction identifiers (TIDs) and service identifiers to differentiate between various communication sessions. In certain implementations, the corenetwork (CN) may generate correlation identifiers using pseudo-random sequence generators such as PN sequences, M-sequences, or Golay sequences. However, it is possible that different readers may receive identical correlation identifiers for the same service request. In such cases, the device may be unable to distinguish whether two paging requests originate from the same reader or from different readers.

[0130] To address this limitation, the present invention proposes two methods for generating unique transaction identifiers.

[0131] Methodi: In one embodiment (Method-1), both the reader identifier and the correlation identifier received from the core network are transmitted together as the transaction identifier. The reader identifier may also function as an associated identifier corresponding to the transaction cycle. When the number of readers and services is relatively small, the reader identifier may be represented using a small number of bits, thereby allowing the correlation identifier to also remain relatively short while still ensuring uniqueness.

[0132] Method-2: In another embodiment (Method-2), a new transaction identifier may be generated using both the correlation identifier received from the core network and the reader identifier. For example, the transaction identifier may be generated by combining these values using techniques such as a Gold sequence generator, replacing selected most significant bits of the correlation identifier with least significant bits of the reader identifier, or performing an XOR operation between the two identifiers. Because a Gold sequence generator produces a new pseudo-random sequence from two input sequences, it can generate unique identifiers whenever either the correlation identifier or the reader identifier differs. As a result, different readers may generate different transaction identifiers for the same service request, and the same reader may generate different transaction identifiers for different services.

[0133] In certain embodiments, Method-1 may provide improved robustness and security when sufficient signaling bits are available for ambient loTcommunication. However, Method-2 may be preferable in scenarios where only a limited number of bits can be transmitted or where the number of readers and services is relatively small.

[0134] FIG. 7 depicts the flowchart (700) depicting a method for unified paging and hybrid random access in a wireless communication network supporting multiple readers and Ambient Internet of Things (A-loT) devices.

[0135] In one embodiment, the reader may comprise a base station or access node configured to provide wireless connectivity to a plurality of Ambient Internet of Things (A-loT) devices. The wireless communication network may include multiple such readers deployed in overlapping or adjacent coverage areas. FIG. 7 illustrates a method for unified paging and hybrid random access operation in the multi-reader environment, thereby enabling controlled device response behaviour and efficient utilization of communication resources in large-scale Ambient loT deployments.

[0136] The method begins at step 705, wherein a reader generates a downlink paging message intended for one or more Ambient loT devices within a wireless communication network supporting multiple readers. The paging message may be generated in response to a service request, device discovery procedure, or inventory command received from a core network entity. The paging message may initiate either a contention -free access (CFA) procedure or a contention-based random access (CBRA) procedure depending on the query type and operational context.

[0137] At step 710, the reader configures the paging message with a unified message structure. In one embodiment, the unified message structure comprises a paging identifier, a message type identifier, a transaction identifier, a reader identifier, a query type indicator, and resource allocation information. The resource allocation information may include time-domain resources and frequency-domain resources allocated for uplink transmission by responding devices.

[0138] In certain embodiments, the unified message structure may further include an indicator specifying whether CFA or CBRA is to be utilized andmay optionally include a CBRA resource start index to distinguish between device-specific dedicated resources and shared random-access resources. The transaction identifier may be generated based on a combination of a reader identifier and a correlation identifier to ensure uniqueness in multireader deployments.

[0139] At step 715, the reader transmits the configured downlink paging message to one or more Ambient loT devices within its coverage area. The transmission may occur over a Physical Random Access Downlink Channel (PRDCH) or an equivalent downlink channel. In multi-reader environments, multiple readers may transmit paging messages during overlapping time intervals, resulting in simultaneous paging reception at certain devices.

[0140] At step 720, the Ambient loT devices receive the paging message and determine whether to respond based on information contained in the unified message structure. Each device evaluates the transaction identifier, reader identifier, and query type indicator included in the paging message.

[0141] The device may compare the received transaction identifier with a stored transaction identifier associated with a previously completed communication session. If the received transaction identifier matches a stored identifier corresponding to a completed transaction from the same reader, the device may discard the paging message to avoid redundant responses. If the transaction identifier does not match the stored identifier, or if the paging message originates from a different reader with a different transaction identifier, the device may determine that a response is required.

[0142] At step 725, one or more Ambient loT devices transmit an uplink response message using the allocated time-domain and frequency-domain resources specified in the paging message. In a contention-free access scenario, device-specific dedicated resources may be utilized. In a contention-based random-access scenario, shared resources may be used, and the device may transmit a random identifier as part of the uplink response to initiate the multi-step random access procedure.At step 730, the reader receives the uplink response message and processes the communication according to either a contention-free access (CFA) procedure or a contention-based random access (CBRA) procedure in the multi-reader environment.

[0143] In the case of CFA, the reader may directly process the received device information and complete the transaction. In the case of CBRA, the reader may perform additional scheduling and acknowledgment operations to complete the multi-step random access sequence. The reader may further update transaction state information and manage resource allocation for subsequent communication slots within an inventory cycle.

[0144] Accordingly, the method illustrated in FIG. 7 enables unified paging, transaction-aware response determination, and hybrid CFA / CBRA operation in multi-reader Ambient loT systems. By incorporating transaction identifiers, reader identifiers, and structured resource allocation within a unified paging message, the method reduces signaling overhead, minimizes redundant transmissions, and enhances scalability and energy efficiency in large-scale Ambient loT deployments.

[0145] FIG. 8 illustrates a network node (800) configured to support unified paging and random-access procedures for Ambient Internet of Things (A-loT) devices in a multi-reader communication environment, in accordance with one embodiment of the present invention.

[0146] The network node 800 may represent, in various embodiments, a reader, a base station, an access node, or any network entity configured to initiate paging procedures and manage random access communication with one or more Ambient loT devices. In certain embodiments, the network node may operate within a 5G-Advanced (5GA) or 6G communication system supporting massive Machine Type Communications (mMTC). The network node 800 may include a network interface 810, a processor 820, a memory 830, and a storage unit 840, each operatively coupled to facilitate communication and processing functions.The network interface (810) may be configured to transmit and receive communication signals over a wireless communication medium. In one embodiment, the network interface (810) is configured to transmit downlink paging messages, including unified MsgO structures, over a Physical Random Access Downlink Channel (PRDCH). The network interface 810 may further be configured to receive uplink response messages, including Msg1 and Msg3, from Ambient loT devices over an uplink random access channel.

[0147] In certain embodiments, the network interface (810) may also facilitate communication with a core network (CN), through which service requests, correlation identifiers, or transaction-related parameters may be received. The network interface (810) may additionally support coordination with other network nodes in a multi-reader deployment scenario.

[0148] The processor (820) may be configured to execute program instructions stored in the memory (830) and / or storage (840) to perform unified paging and random-access operations in accordance with the present invention. In one embodiment, the processor (820) is configured to generate a unified downlink paging message comprising a paging identifier, a message type identifier, a transaction identifier, a reader identifier, a query type indicator, and resource allocation information including time-domain and frequency-domain resources.

[0149] The processor (820) may further determine whether contention-free random access (CFRA) or contention-based random access (CBRA) is to be utilized and may incorporate an appropriate indicator within the unified message structure. In certain embodiments, the processor (820) may also include a CBRA resource start index to distinguish between dedicated CFRA resources and shared CBRA resources.

[0150] In another embodiment, the processor (820) may be configured to generate transaction identifiers based on a combination of a reader identifier and a correlation identifier received from the core network. The transaction identifier may be generated using pseudo-random sequence techniques,XOR operations, bit-replacement mechanisms, Gold sequence generation, or other suitable combination methods. Such generation mechanisms enable differentiation of service requests in multi-reader environments and allow Ambient loT devices to distinguish between paging messages originating from different readers or corresponding to different services.

[0151] The processor (820) may further be configured to receive uplink messages from one or more Ambient loT devices and to process random identifiers included in such messages. Based on the received identifiers and stored transaction information, the processor (820) may schedule device transmissions, allocate communication resources, and manage inventory cycles initiated by the network node. In multi-reader scenarios, the processor (820) may coordinate transaction identifiers and resource allocation information to reduce the probability of collision, redundant responses, and inefficient resource utilization.

[0152] The memory (830) may store executable instructions that, when executed by the processor (820), cause the network node 800 to perform the unified paging, hybrid CFRA / CBRA operation, and transaction management procedures described in connection with FIGS. 1 through 6. The memory (830) may also store transaction identifiers, service identifiers, device random identifiers, scheduling information, inventory cycle parameters, and multi-reader coordination parameters. In certain embodiments, the memory (830) may temporarily store received uplink message data and maintain state information associated with ongoing communication sessions.

[0153] The storage unit (840) may provide non-volatile storage for configuration parameters and historical communication records. In one embodiment, the storage unit (840) may maintain predefined time-slot and frequency-slot configurations, reader identifiers, correlation identifier generation parameters, random identifier generation algorithms, and security-related configuration data. The storage unit (840) may further storealgorithms for generating unified message structures and managing hybrid random access procedures.

[0154] Accordingly, the network node 800 illustrated in FIG. 8 enables unified paging, hybrid contention-free and contention-based random access, and robust multi-reader transaction management in large-scale Ambient loT deployments. By integrating unified message generation, transaction identifier management, and resource allocation control within a single network entity, the network node 800 supports scalable, powerefficient, and collision-aware communication in 5G-Advanced and 6G mMTC environments.

[0155] Accordingly, the proposed system introduces unified signaling structures for both downlink paging messages and uplink response messages while enabling coordinated operation of ambient loT devices in multi-reader environments. The invention further defines mechanisms for transaction identification, device response decision logic, and hybrid contention-free and contention-based random-access procedures, thereby improving scalability, resource utilization, and communication efficiency in large-scale Ambient loT deployments within 5G Advanced and 6G networks.

[0156] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.

Claims

We Claim:

1. A method for Ambient Internet-of-Things (loT) paging and random access in a wireless communication network supporting multiple readers, the method comprising:generating, a downlink paging message intended for one or more Ambient loT devices;configuring, the downlink paging message to include a unified message structure applicable to both contention-free access (CFA) and contention-based random access (CBRA), the unified message structure comprising:a paging identifier configured to indicate whether the paging message corresponds to an initial paging transmission or a repeated paging transmission;a message type identifier indicating a type of the downlink paging message;a transaction identifier associated with a transaction cycle or service request;a reader identifier identifying the reader transmitting the downlink paging message;a query type indicator indicating whether the paging message is directed to a single device, multiple devices, a group of devices, or all devices within a coverage area of the reader, and resource allocation information;transmitting, the downlink paging message to the one or more Ambient loT devices; andreceiving, an uplink response message transmitted by at least one Ambient loT device in response to the downlink paging message, wherein the unified message structure supports both contention -free access (CFA) and contention-based random access (CBRA) for communication with Ambient loT devices in a multi-reader environment.

2. The method as claimed in claim 1, wherein the unified message structure further comprises an indicator specifying whether the randomaccess procedure corresponds to contention-free access (CFA) or contention-based random access (CBRA).

3. The method as claimed in claim 1, wherein the unified message structure further comprises a CBRA resource start index indicating a starting resource index associated with contention-based random-access resources.

4. The method as claimed in claim 1 , wherein the resource allocation information comprises time domain resource information and frequency domain resource information indicating resources allocated for transmission of the uplink response message.

5. The method as claimed in claim 1, wherein the downlink paging message is configured to support paging of:a single Ambient loT device;multiple specified Ambient loT devices;a group of Ambient loT device; orall Ambient loT devices within the coverage area of the reader.

6. The method as claimed in claim 1, wherein the uplink response message comprises a unified uplink message structure including:a random identifier generated based on a device identifier and a device type;a message type identifier;a data size indicator;a device energy status indicator;a data presence indicator; andupper layer data.

7. The method as claimed in claim 1 , further comprising associating the transaction identifier with a transaction cycle such that Ambient loT devices that have completed the transaction cycle refrain from responding to subsequent paging messages having the same transaction identifier.

8. The method as claimed in claim 1, wherein the reader identifier enables an Ambient loT device to distinguish paging messages transmitted from different readers in a multi-reader deployment scenario.

9. The method as claimed in claim 1 , wherein the transaction identifier is configured to enable an Ambient loT device to determine whether to respond to the downlink paging message based on comparison with a previously stored transaction identifier.

10. The method as claimed in claim 9, wherein the Ambient loT device is configured to discard a received paging message when the transaction identifier matches a previously stored transaction identifier associated with a completed transaction cycle for the same reader.

11. The method as claimed in claim 1, wherein the transaction identifier is generated based on a correlation identifier and the reader identifier using one of:a Gold sequence,an exclusive-OR (XOR) operation, orreplacement of one or more most significant bits of the correlation identifier with least significant bits of the reader identifier.

12. A system for Ambient Internet-of-Things (loT) paging and random access in a wireless communication network supporting multiple readers, comprising:a reader configured to:generate a downlink paging message for one or more Ambient loT devices;configure the downlink paging message to include a unified message structure applicable to both contention-free access (CFA) and contention-based random access (CBRA), the unified message structure including a paging identifier, a message type identifier, a transaction identifier, a reader identifier, a query type indicator, and resource allocation information; andtransmit the downlink paging message to the one or more Ambient loT devices; andone or more Ambient loT devices configured to transmit an uplink response message to the reader in response to the downlink paging message.

13. The system as claimed in claim 12, wherein the resource allocation information comprises time domain resources and frequency domain resources for uplink transmission.

14. The system as claimed in claim 12, wherein the unified message structure further comprises an indicator specifying whether contention-free access or contention-based random access is to be performed.

15. The system as claimed in claim 14, wherein the unified message structure further comprises a CBRA resource start index identifying contention-based random-access resources.

16. The system as claimed in claim 12, wherein the reader is configured to initiate paging of a single device, multiple devices, a group of devices, or all devices within a coverage area.

17. The system as claimed in claim 12, wherein the Ambient loT device is configured to generate the uplink response message including a random identifier derived from a device identifier and device type.

18. The system as claimed in claim 12, wherein the Ambient loT device determines whether to respond to the downlink paging message based on a comparison between the transaction identifier included in the paging message and a stored transaction identifier.

19. The system as claimed in claim 18, wherein the Ambient loT device discards the downlink paging message when the transaction identifier matches the stored transaction identifier, and the paging message originates from the same reader.

20. The system as claimed in claim 18, wherein the Ambient loT device responds to the downlink paging message when the transaction identifier differs from the stored transaction identifier.

21. The system as claimed in claim 12, wherein the reader processes the uplink response message according to either a two-step contention-free access procedure or a four-step contention-based random-access procedure.

22. A network node for supporting Ambient Internet-of-Things (loT) paging and random access in a wireless communication network supporting multiple readers, the network node comprising:a network interface (810) configured to communicate with one or more Ambient loT devices;a processor (820) operatively coupled to the network interface (810); anda memory (830) and storage (840) communicatively coupled to the processor (820), the memory storing instructions which, when executed by the processor (820), cause the network node to:generate a downlink paging message intended for one or more Ambient loT devices;configure the downlink paging message to include a unified message structure applicable to both contention-free access (CFA) and contention-based random access (CBRA), the unified message structure comprising: a paging identifier, a message type identifier, a transaction identifier, a reader identifier, a query type indicator, and resource allocation information;transmit, via the network interface (810), the downlink paging message to the one or more Ambient loT devices; andreceive, via the network interface (810), an uplink response message from at least one Ambient loT device in response to the downlink paging message,wherein the unified message structure enables the network node to initiate random access communication with the one or more Ambient loT devices using either contention-free access (CFA) or contention-based random access (CBRA) in a multi-reader environment.

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