Resource allocation and frame structure of ambient IoT

Abstract

This invention introduces an energy-efficient communication protocol for Ambient IoT, integrating Slotted ALOHA with RF energy harvesting to enable reliable interaction between ultra-low-power, battery-less devices and 5G / 6G base stations or relay UEs. Devices first harvest energy from a Carrier Wave (CW) signal, followed by a structured five-message exchange (Msg0–Msg4) handling synchronization, random access, data transmission, and acknowledgments. Time-frequency resources are dynamically allocated based on device energy levels and random IDs, reducing collisions and improving throughput. Control signals use differential encoding for robustness. Each message is framed with a preamble and postamble, allowing the device to detect the start and end of the signal. Padding is inserted before the preamble to ensure alignment with NR OFDM symbol boundaries. A Slotted ALOHA-based retransmission strategy enhances channel reuse. Eliminating dedicated RFID readers, this approach supports long-range, interference-managed communication, offering a scalable, low-latency, and cost-effective solution for massive machine-type communication (mMTC) in next-generation Ambient IoT networks.

Description

[0001]Resource allocation and frame structure of Ambient IoT Field of the Invention The present invention relates to wireless communication technology, specifically to methods and systems for resource allocation, physical and MAC layer frame structure design, and random-access mechanisms for ultra-low power, battery-less Ambient Internet-of-Things (IoT) devices communicating with 5G Advanced and 6G networks. Background of the Invention Wireless communication systems have continuously evolved across generations shifting from voice and SMS-centric 2G networks to today’s highly intelligent, low-latency, and high-capacity 5G systems. As we transition toward 6G, the focus expands beyond enhanced mobile broadband (eMBB) and ultra-reliable low-latency communication (URLLC) to include massive machine-type communication (mMTC), which underpins large-scale Internet of Things (IoT) ecosystems. A key enabler of this evolution is the Ambient Internet of Things (A-IoT)—a paradigm that supports battery-less or ultra-low-power devices capable of operating through energy harvested from ambient sources, such as RF signals. A-IoT is particularly well-suited for applications involving device identification, tracking, and lightweight data transmission in power- constrained environments. These include use cases like asset tracking in logistics chains, inventory management in smart warehouses, infrastructure condition monitoring, and automated toll collection systems where large numbers of passive or semi-passive devices must reliably communicate with network infrastructure without the maintenance overhead of batteries. Existing solutions, such as RFID-based systems, offer low-power backscatter communication capabilities, but they suffer from several limitations. Their communication range is restricted (typically 1–2 meters), they require dedicated reader infrastructure and are generally limited to one- to-one communication. These constraints result in scalability challenges, interference issues, and communication bottlenecks, especially in high- density deployment scenarios. Moreover, such systems lack dynamic scheduling, energy awareness, and the ability to leverage the advanced capabilities of modern 5G and future 6G networks. To overcome these challenges, there is a growing need for next- generation A-IoT communication frameworks that can integrate seamlessly with NR (New Radio) base stations and user equipment (UE) in cellular networks. This includes the ability for battery-less devices to harvest energy from high-power signals transmitted by base stations, initiate communication autonomously, and support parallel access by a large number of devices with efficient medium access control (MAC) and physical layer (PHY) enhancements. Objective of the Invention The principal objective of this invention is to extend the communication range of battery-less Ambient IoT devices by enabling backscatter communication using high-power carrier wave (CW) signals emitted from base stations or user equipment (UE), thereby improving coverage in large-scale deployments. Another objective of this invention is to provide a complete Ambient IoT communication framework that spans low-level signal design (e.g., waveform generation, slot timing) and high-level protocol operation (e.g., message flow, scheduling), ensuring seamless integration with 5G and future 6G networks. Another objective of this invention is to dynamically allocate time and frequency domain resources based on device energy levels and network conditions, enabling energy-aware and contention-resilient scheduling for massive numbers of ultra-low power devices. Another objective of this invention is to reduce latency and transmission collisions in dense IoT environments by implementing a slotted ALOHA-based random-access protocol tailored for energy-constrained Ambient IoT scenarios. Another objective of this invention is to enhance system scalability and reduce interference by employing frequency diversity and spatial beamforming techniques across multiple antenna surfaces for more efficient multi-device communication. A further objective of this invention is to enable self-sustaining, maintenance-free operation of Ambient IoT devices through RF energy harvesting from CW signals, eliminating dependence on batteries and extending device lifetime in field deployments. Summary of the Invention This invention relates to a method and system for enabling wireless communication between a transceiver or reader and a plurality of ultra-low power, battery-less Ambient Internet of Things (IoT) devices. The invention addresses limitations in existing passive IoT and backscatter systems, such as restricted communication range, inefficient resource management, high collision probability, and poor compatibility with emerging wireless standards including 5G and 6G. It provides a complete communication framework that includes both physical layer waveform construction and higher-layer access and scheduling behavior, specifically designed for dense, energy-constrained deployment environments. To overcome these limitations, the invention employs a transceiver that transmits a carrier wave (CW) signal during a charging window at the beginning of each communication cycle. This CW signal enables battery- less Ambient IoT devices to harvest energy and activate their communication functionality. Following energy harvesting, the transceiver broadcasts a paging message (Msg0) to detect available devices. Devices respond with a random access message (Msg1) containing a temporary identifier, energy status, and message size. The transceiver processes these responses and transmits a resource allocation message (Msg2) as random access response, assigning subcarriers and OFDM time slots for uplink communication. Scheduled devices transmit uplink data via Msg3, followed by Msg4 feedback from the transceiver containing acknowledgment or retransmission instructions. The invention further defines physical layer signals referred to as the Physical Reader to Device Channel (PRDCH) and Physical Device to Reader Channel (PDRCH) constructed by encoding Layer 2 payloads, applying a cyclic redundancy check (CRC), performing line coding, and modulating the resulting frame. These signals include preambles for synchronization and postambles to denote frame completion. Resource allocation is handled by a scheduler that assigns communication resources dynamically based on each device’s energy status and network conditions. A slotted ALOHA-based random access mechanism is used to manage contention and improve channel access efficiency across multiple devices. The transceiver may be implemented as a base station or as user equipment (UE) operating in relay mode, and may include multiple antenna surfaces capable of beam steering at alternating frequencies to improve spatial diversity and signal reception. The system supports continuous or slotted CW signal transmission for simultaneous device charging and backscatter communication. Additionally, communication security and device privacy are supported through the use of randomly generated temporary identifiers and configurable encoding schemes. The invention enables energy-efficient, low-latency, and scalable communication with battery-less Ambient IoT devices and can be integrated into modern 5G / 6G cellular infrastructures. It is applicable to a wide range of use cases such as vehicle tracking, asset tracking, smart logistics, and environmental monitoring, particularly in scenarios requiring large-scale, low-maintenance device connectivity over extended communication ranges. Brief description of the drawings 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. FIG.1 demonstrates the Proposed system model (100) according to a preferred embodiment of the present invention. FIG. 2(A) presents the base station (BS) in the read state (200A), according to one embodiment of the present invention. FIG.2(B) represents the Intermediate node as the reader (200B), in accordance with an embodiment of the invention. FIG.3(A) outlines Option 1, where the device stores energy from the carrier wave (CW) signal at the beginning of every slot (300A), according to a preferred embodiment of the present invention. FIG.3(B) depicts Option 2, where the reader continuously transmits CW signal (300B), according to one embodiment of the present invention. FIG.4 shows a Flow diagram of communication from Msg0 to Msg4 between reader and device (400), in accordance with an embodiment of the invention. FIG.5(A) illustrates the reader transmitting Msg0, which carries the paging signal (500A), in accordance with an embodiment of the invention. FIG. 5(B) depicts the device receiving Msg0 (500B), in accordance with an embodiment of the invention. FIG.6(A) shows the device transmitting Msg1 in response to Msg0 from the reader (600A), according to a preferred embodiment of the present invention. FIG.6(B) presents the reader receiving Msg1 (600B), according to a preferred embodiment of the present invention. FIG. 7(A) depicts Reader transmits Msg2 to allocate time and frequency domain resources to devices (700A) according to a preferred embodiment of the present invention. FIG.7(B) shows the device receiving Msg2 from the reader (700B), according to a preferred embodiment of the present invention. FIG. 8(A) depicts the device transmitting Msg3 after receiving resources from the reader (800A), according to a preferred embodiment of the present invention. FIG. 8(B) shows the device transmitting Msg3 after receiving resources from the reader (800B), in accordance with an embodiment of the invention. FIG. 9(A) illustrates the reader transmitting Msg4 in response to Msg3 (900A), according to a preferred embodiment of the present invention. FIG.9(B) presents the device receiving Msg4 (900B), according to a preferred embodiment of the present invention. FIG. 10(A) shows a Differential encoding of control information (1000A), in accordance with an embodiment of the invention. FIG. 10(B) presents a Differential decoding of control information (1000B), in accordance with an embodiment of the invention. FIG.11 illustrates Slotted Aloha mechanism for random access to the channel to send Msg1 from the device (1100), according to a preferred embodiment of the present invention. 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. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures. Detailed Description of the Invention 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. 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. 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. 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. 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 would limit 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. Figure 1 illustrates a preferred embodiment of the system model for Ambient Internet of Things (IoT) communication (100), which enables efficient, large-scale interaction between ultra-low-power devices and a central network entity. The system includes a New Radio (NR) base station (BS) configured to communicate with a plurality of Ambient IoT devices deployed across a multilane roadway, such as in a vehicle tracking or tolling application. The Ambient IoT devices are characterized by extremely low energy consumption, typically below 10 microwatts, and are capable of operating without a dedicated power source or battery. These devices are designed to harvest energy from a carrier wave (CW) signal transmitted by the BS, and to use that harvested energy to establish communication by modulating and reflecting the CW signal, a technique known as backscatter communication. This method reduces power requirements significantly and supports maintenance-free operation in long-duration deployments. The base station is equipped with a plurality of antenna surfaces configured to transmit multiple steered directional beams across the coverage area. These beams operate at distinct center frequencies, denoted as f₁ and f₂, where f₁ corresponds to a lower frequency band and f₂ corresponds to a higher frequency band. In the illustrated embodiment, the beams operating at frequency f₁ are spatially separated and reused in non-overlapping sectors to maximize spectral efficiency. An additional beam operating at frequency f₂ is positioned between the f₁ coverage sectors to provide intermediate coverage. This beam configuration leverages both frequency and spatial diversity to enable simultaneous communication with a large number of Ambient IoT devices distributed across the environment, thereby enhancing capacity, reducing interference, and supporting high- density device deployments. Each vehicle includes an Ambient IoT tag that receives the CW signal from the BS and uses it to power its internal circuitry for communication. Upon receiving sufficient energy, the tag responds by backscattering modulated data, which may include a unique device identifier, device type, and other metadata. The communication process is synchronized and managed through defined uplink and downlink message structures, enabling organized and reliable data exchange between the BS and multiple devices simultaneously. The steered beam configuration, combined with the use of multiple frequencies, allows for efficient use of available spectrum and reduces interference among neighbouring devices. This beam-based and frequency-diverse architecture supports large-scale deployments with high device density, minimizing latency and optimizing network throughput. The spatial reuse of frequency bands, such as using f₁ for non-overlapping sectors, further enhances the system's capacity and coverage. This system is well-suited for asset tracking applications, where tags affixed to mobile or stationary assets such as containers, equipment, or inventory units can communicate with the base station over extended distances without the need for local RFID readers or dedicated scanning infrastructure. The architecture enables scalable, long-range, and low- latency communication in environments requiring high reliability and ultra- low power consumption. The design eliminates the need for location- specific hardware installations, thereby reducing infrastructure complexity and overall deployment costs in large-scale asset monitoring and logistics operations. Figures 2(A) and 2(B) illustrate two operational configurations of the Ambient Internet of Things (IoT) communication framework (200A and 200B), demonstrating distinct modes of interaction between Ambient IoT devices and the network infrastructure based on their proximity to a New Radio (NR) base station (BS). In Figure 2(A), the system operates in a direct communication mode (200A), wherein the Ambient IoT device resides within the effective communication range of the BS. In this configuration, the BS functions directly as the reader and establishes a communication link with one or more Ambient IoT devices without requiring any intermediate nodes. The BS transmits a Carrier Wave (CW) signal, which is received by the ultra-low power Ambient IoT devices to harvest energy. Once sufficiently energized, the devices transmit uplink data to the BS using backscatter modulation, whereby the information is reflected and encoded over the incident CW signal. This mode is optimal when the devices are located near the BS and can reliably receive the carrier signal. The BS can concurrently manage multiple devices in its vicinity, enabling efficient large-scale communication with minimal latency and without additional infrastructure. In Figure 2(B), the system employs an intermediate communication mode (200B) for scenarios where Ambient IoT devices are positioned outside the BS’s direct communication range. In such cases, a User Equipment (UE) node is used as an intermediary reader to bridge the connection between the device and the BS. The UE, positioned strategically between the BS and the remote device, first transmits the Carrier Wave (CW) signal to enable the device to harvest energy. Once the device responds via backscatter communication, the UE captures the signal and relays the information to the BS. This mode ensures continued data exchange when the device cannot directly interface with the BS due to distance or environmental constraints. In both configurations, two physical communication channels are utilized to support bidirectional data exchange. The Physical Reader-to- Device Channel (PRDCH) facilitates downlink (DL) transmissions from the reader (BS or UE) to the Ambient IoT device, while the Physical Device-to- Reader Channel (PDRCH) is used for uplink (UL) transmissions from the device back to the reader. According to 3GPP Radio Access Network (RAN) specifications for Ambient IoT, Ambient IoT device type-1 relies exclusively on RF-based energy harvesting. Since these devices do not possess alternative ambient energy sources, the reader must first transmit the Carrier Wave signal prior to any DL data frame. This ensures that sufficient energy is accumulated at the device for subsequent communication. The invention further defines two timing diagram models to accommodate the capabilities of different readers. These timing configurations specify the sequencing and duration of the CW signal transmission, followed by the DL and UL communication phases, ensuring synchronization and power availability for the device. Whether the CW signal is transmitted intermittently or continuously depends on the antenna configuration and transmission capability of the reader. Figures 3(A) and 3(B) illustrate two alternative operational modes Option 1 and Option 2, respectively for energy harvesting and communication in an Ambient Internet of Things (IoT) system (300A and 300B). These figures demonstrate how Ambient IoT devices utilize Radio Frequency (RF) energy harvested from a Carrier Wave (CW) signal transmitted by a reader such as a base station (BS) or a user equipment (UE) node to enable low-power, bidirectional communication under varying deployment conditions. In Figure 3(A), referred to as Option 1 (300A), the system operates in a time-synchronized, slot-based mode. This configuration is suitable when the reader has a single antenna surface, limiting it to transmit one steered directional beam at a time. At the beginning of each communication slot, the reader transmits a Carrier Wave (CW) signal for a predefined duration, denoted as TCW, allowing the Ambient IoT device to harvest energy and store it temporarily in its internal energy storage component. Following this energy harvesting phase, the reader transmits the PRDCH frame to initiate communication. The PRDCH contains control or system-level information that the device must process. This configuration relies on precise timing; insufficient CW transmission duration or misaligned slots may result in the device being undercharged and unable to participate in communication. While the predictability of this approach aids in synchronization and resource planning, it may reduce flexibility in dynamic environments. In Figure 3(B), corresponding to Option 2 (300B), the system adopts a more flexible and continuous mode of energy harvesting and communication. This mode is applicable when the reader is equipped with multiple antenna surfaces and is capable of simultaneously transmitting a continuous, unmodulated Carrier Wave (CW) signal alongside active communication signals. In this configuration, the Ambient IoT device continuously harvests RF energy from the CW signal and monitors its internal energy level. The device activates its receiver when either the harvested energy reaches a certain threshold (e.g., X% of its maximum energy capacity) or when the charging duration exceeds TCW. Once activated, the device receives the PRDCH frame. Immediately following downlink reception, the device responds using backscatter modulation, transmitting its uplink data over the Physical Device-to-Reader Channel (PDRCH) by reflecting the same CW signal. This simultaneous CW and PRDCH transmission capability increases communication efficiency and minimizes latency by enabling immediate uplink response without requiring active RF transmission circuitry in the device. The selection between Option 1 and Option 2 depends on reader capabilities and the application environment. For example, in vehicle tolling applications, Ambient IoT tags affixed to vehicles can engage in structured slot-based communication at toll plazas (Option 1), or in high-speed highway environments, where flexible and continuous energy harvesting is advantageous (Option 2). Similarly, in asset tracking applications, where tags may be attached to containers, pallets, or equipment distributed across warehouses, ports, or transit vehicles, Option 2 enables seamless communication in settings with irregular movement patterns or unpredictable energy availability. Option 1 may be deployed in more controlled environments with synchronized device access patterns, such as industrial inventory lines or loading docks. Figure 4 presents the detailed time-sequenced communication between a reader (such as a 5G / 6G base station or user equipment acting as a relay) and a battery-less Ambient IoT device (400). This communication protocol consists of a structured exchange of five messages (Msg0 to Msg4) and is carefully synchronized to manage energy harvesting, resource allocation, and low-power data transmission using backscatter communication. At the beginning of each communication cycle, the reader transmits a Carrier Wave (CW) signal for a fixed duration, referred to as TCW (Charging Window). This unmodulated carrier signal allows the battery-less Ambient IoT device to harvest radio frequency (RF) energy, which is used to power its internal components such as non-volatile memory, clock synchronization circuitry, and backscatter transmission logic. The transmission during the Charging Window is essential, as the device is unable to initiate or participate in any communication activity until it has acquired sufficient energy from this CW signal. Following the TCW period, the reader sends Msg0 to the device during a time interval marked as T0. Msg0 is a paging or inventory command that includes physical layer synchronization information (such as start-of-frame indicators and clock acquisition sequences) and higher-layer system information. This message initiates the discovery phase, prompting all powered-up devices in the vicinity to synchronize with the reader’s timing and prepare to respond. After Msg0, there is a short guard interval (TGap A) to account for processing and propagation delay, where TGapA or Toffset1 is the time interval from the end of the R2D transmission triggering random access to the starting time of the first Msg1 time domain resource. The device, upon receiving Msg0 and successfully synchronizing, sends Msg1 back to the reader during T1. Msg1 includes a randomly generated device ID, the energy status of the device, and the size of the data it intends to transmit. This uplink message acts as a request to communicate, signaling to the reader that the device is active and ready for data exchange. The random ID helps the reader distinguish between multiple simultaneous devices and is critical for downstream scheduling. Once Msg1 is received, the reader introduces another guard interval, TGap B, to process the incoming messages and determine which devices will be granted access to the communication channel. It then sends Msg2 to the devices during T2. Msg2 contains resource allocation information, including the mapping of random IDs to frequency-domain subcarriers and time-domain OFDM slots, as well as the expected duration T3 for each device’s uplink transmission. This allocation allows the reader to control simultaneous device communication in an efficient and interference-free manner. After Msg2, another short pause (TGap C) gives the device time to prepare its actual data, where TGapC ot Toffset3 which is the time interval from the end of a R2D transmission for Msg2 to the starting time of the corresponding Msg3 time domain resource, from the device perspective. The device then sends Msg3 during T3, using the allocated subcarrier and time slot. Msg3 carries the uplink payload, including the device’s actual identifier, type, and application-specific data. This message is constructed with error-checking features like CRC (Cyclic Redundancy Check), line coding, and optional differential encoding. Additionally, the signal is aligned with the NR OFDM frame structure using zero-padding if required. Then reader waits through TGap D to decode Msg3 and then transmits Msg4 during T4. Msg4 includes either an ACK (acknowledgment) or NAK (negative acknowledgment). If Msg3 was successfully decoded, the reader sends an ACK, informing the device that no further communication is needed. The device then powers off to save energy. If a NAK is received, indicating decoding failure, the device calculates the appropriate timing for retry and reenters the communication sequence in a future slot. After Msg4, the figure shows a final CW signal transmission from the reader to the device, again for a duration of TCW. This signal plays a dual role: (1) it recharges the Ambient IoT device again to prepare for the next communication cycle, and (2) it guarantees that devices with insufficient energy in the current cycle can harvest enough power to attempt communication in the next round. This step ensures fairness and reliability in the overall scheduling scheme, especially in high-density deployments. Lastly, the figure includes a TGapS interval following Msg4 and before the next CW transmission. TGapS (Sleep / Spacing Gap) is a reset window a short pause that ensures any residual processing, retries, or power-down operations are complete before the next communication cycle begins. It separates two full iterations of the Msg0–Msg4 exchange sequence and maintains temporal isolation between cycles. Each message (Msg0 through Msg4) contains a preamble and postamble. The preamble includes the start indicator and clock acquisition part, enabling synchronization between the reader and the device. The postamble denotes the end of the message, ensuring proper message framing. In another embodiment, the method may further include computing a timing offset (Toffset) at each Ambient IoT device. The Toffset is derived from synchronization information embedded in Msg0, including start-of-frame indicators and clock acquisition sequences. This timing offset enables each device to align its uplink transmissions such as Msg1 and Msg3 with the orthogonal frequency-division multiplexing (OFDM) symbol boundaries defined by the NR frame structure, thereby minimizing symbol misalignment and improving decoding accuracy. This method may also include introducing a set of inter-message time gaps (TGap) between successive message exchanges, including but not limited to TGapA, TGapB, TGapC, TGapD, and TGapS. These gaps serve to isolate communication events, absorb timing variations due to propagation delays or processing latencies, and accommodate the energy harvesting behavior of battery-less devices. For example, TGapA allows sufficient time for a device to process Msg0 and respond with Msg1, while TGapC provides a buffer for preparing the uplink data transmission in Msg3 after receiving Msg2. In certain embodiments, the duration of each TGap may be dynamically adjusted based on one or more parameters, such as the number of active devices, observed contention or collision rates, processing delays, or the availability of time-frequency resources. This dynamic adjustment allows the method to adapt efficiently to both sparse and dense deployment scenarios, reducing contention and latency. Before transmitting each uplink message, particularly Msg3, the method may include applying zero-padding to the message frame based on the previously computed Toffset. This ensures alignment with NR OFDM symbol boundaries and allows seamless uplink integration with NR receivers. The combination of timing offset computation, adaptive inter- message spacing, and symbol-aligned padding results in a highly synchronized and energy-efficient communication method suitable for ultra- low power Ambient IoT applications. Figure 5(A) illustrates the process by which the reader transmits Msg0 (500A), initiating the communication sequence within an Ambient IoT framework. Msg0, a Reader-to-Device (R2D) signal, functions as a paging message, designed to detect and activate any Ambient IoT devices within range. The transmission of Msg0 begins at the Layer 2, where system information and application-specific data are assembled to form the R2D information bits. These bits include essential instructions such as system identification and radio resource control (RRC) triggers that help establish and manage future connections between the reader and the device. The information bits are passed through a CRC (Cyclic Redundancy Check) attachment block, followed by line coding, ensuring robust error detection and signal integrity. In parallel, a R2D synchronization signal is generated, which consists of two critical components: the Start Indicator, marking the beginning of the message, and the Clock Acquisition signal, which helps the device align its internal clock with the reader's transmission. These signals are processed by the preamble sequence generator, which builds the preamble frame of Msg0. After synchronization and coding, the processed signal enters the OOK-1 / OOK-4 modulation and OFDM generation block, forming the main payload known as PRDCH (Physical R2D Channel). This segment carries the actual paging data. Simultaneously, postamble sequence generation occurs to indicate the end of the message. The complete Msg0 frame is then constructed by concatenating the preamble, PRDCH, optional padding (used for alignment), and postamble. This message is then transmitted wirelessly to detect and activate devices within range. Figure 5(B) shows the corresponding reception process where an Ambient IoT device receives Msg0 from the reader (500B). Upon receiving the wireless signal, the device begins by identifying and processing the preamble, which contains a Start Indicator and a Clock Acquisition signal. These elements are detected by the preamble sequence detector, enabling the device to synchronize its clock with the reader's and to recognize the beginning of the message. Proper synchronization is essential, especially for ultra-low-power devices that rely on externally provided timing. The PRDCH signal is then demodulated using the OOK-1 / OOK-4 demodulation process, which extracts the physical layer data from the received signal. This data is decoded and passed through a CRC check to verify its integrity. The correctly decoded Layer 2 bits, which include system information and data, form the paging signal that informs the device of the upcoming steps for communication setup. Simultaneously, the postamble sequence is detected using a postamble detector, confirming the end of the Msg0 message. If applicable, padding ensures that the message frame aligns with the NR OFDM symbol boundary, enabling the device to interpret the signal within the expected timing structure. Figure 6(A) presents the structure and transmission process of Msg1 (600A), initiated by the Ambient IoT device following the reception of Msg0 from the reader. Msg1 serves as the first uplink message in the communication cycle. This message includes essential Layer 2 information such as a randomly generated ID, the message size indicating the volume of data to be transmitted in the subsequent slot, and the device’s energy status, among other operational indicators. These components are classified into control information and data. The message formation begins with the attachment of a Cyclic Redundancy Check (CRC) to the data, ensuring error detection capabilities. The CRC-appended data then passes through a line coding stage to prepare the bits for modulation. The resulting bitstream enters the modulation block, which applies either OOK (On-Off Keying), BPSK (Binary Phase-Shift Keying), or BFSK (Binary Frequency-Shift Keying), depending on the system configuration. Alongside data preparation, the device generates a synchronization signal consisting of two critical parts: a Start Indicator, which signifies the beginning of the message, and a Clock Acquisition signal, which allows time alignment with the reader’s clock. These synchronization components are processed by a preamble sequence generator, forming the initial section of Msg1. The final signal structure includes four components: the Preamble, the PDRCH (Physical D2R Channel), optional Padding, and the Postamble. The Postamble is produced using a sequence generator and signals the end of Msg1. Padding is used to align the signal to the NR OFDM symbol boundary, ensuring precise transmission timing. Padding is inserted before postamble. Once constructed, Msg1 is transmitted from the device to the reader, signaling the device's intent to initiate data exchange. Figure 6(B) illustrates the reception and processing of Msg1 by the reader (600B). Upon arrival, the Preamble section is detected by the preamble sequence detector, which identifies the Start Indicator and Clock Acquisition components. These allow the reader to synchronize its timing with the device transmission. Following synchronization, the PDRCH is passed through a demodulation block, which interprets the signal using the correct modulation scheme OOK, BPSK, or BFSK. The demodulated signal enters the decoding stage, which reconstructs the original bitstream. A CRC check is then applied to validate the integrity of the received data. This results in successful extraction of the Layer 2 D2R information, including the random ID, message size, and the device’s energy status. The energy status bits guide the reader in determining whether the device possesses sufficient energy to complete the communication cycle. If energy is insufficient, the reader may choose to withhold resource allocation, allowing the device to recharge using the next CW signal and retry in a later slot. The message concludes with a Postamble, detected using a postamble sequence detector, confirming the completion of Msg1. Any Padding present ensures that the signal maintains alignment with NR OFDM symbol boundaries. This alignment minimizes bit errors and ensures compatibility with 5G NR physical layer structure. Figure 7(A) outlines the reader's process for generating and transmitting Msg2 (700A), a critical downlink message that conveys time and frequency domain resource allocation to the Ambient IoT devices. Msg2 is sent only to those devices that have successfully transmitted Msg1, signaling their presence and readiness for communication. The reader first evaluates the incoming Msg1s by considering both the energy status of each device and the available subcarriers in its own spectrum resources. The reader then allocates one subcarrier per device, associating it with a unique random ID. In situations where the number of responding devices (n) exceeds the available subcarriers or frequency domain resources (n^c), the reader limits allocation to the n^c most eligible devices, typically based on available energy or queueing priority. Devices that do not receive allocation in the current cycle are deferred to the next slot. At the physical layer, the Layer 2 information including control information and data such as random IDs, assigned frequency resources, time-domain resources such as, OFDM slot indices, and the T₃ value (representing the maximum duration for Msg3 transmission) is compiled. This data undergoes CRC attachment followed by line coding to prepare it for modulation. Simultaneously, a synchronization signal consisting of a Start Indicator and a Clock Acquisition component is created to aid in alignment and timing at the device side. These elements form the preamble, generated using a dedicated preamble sequence generator. The encoded and modulated message (e.g., using OOK-1 / OOK-4 schemes with OFDM) forms the PRDCH (Physical Reader-to-Device Channel), which is then framed with the preamble, optional padding (for OFDM symbol boundary alignment), and a postamble indicating the end of the message. The result is Msg2, which the reader transmits to distribute communication resources among the devices effectively. Knowing the T3 value the devices can calculate the time to receive ACK / NAK acknowledgement. Figure 7(B) represents the reception and interpretation of Msg2 by the Ambient IoT device (700B). Msg2, transmitted as a downlink signal from the reader, carries detailed scheduling and resource allocation information essential for enabling the next stage of uplink communication. Upon receiving the message, the device first detects the preamble using a preamble sequence detector, identifying the Start Indicator and synchronizing its internal clock using the Clock Acquisition signal. The PRDCH segment of Msg2 is then demodulated and decoded to extract the Layer 2 payload. The device performs a CRC check to verify the integrity of the received information. The payload provides the device with its assigned subcarrier, time-domain resource, and the corresponding random ID, confirming that it has been granted a communication opportunity in the current slot. A crucial parameter included is the T₃ value, which specifies the maximum duration allocated for Msg3 this helps the device determine how long it may transmit its data in the upcoming uplink phase and wait to receive ACK / NAK. Depending on the configuration, the slot duration for Msg3 can be either fixed or variable. For fixed slots, T₃ is predefined based on the system’s upper message size limit. In the variable slot scenario, T₃ is dynamically calculated based on the maximum value of the payload size the devices plan to transmit. This adaptive scheduling ensures optimal utilization of spectrum and supports devices with varying data requirements. The Msg2 frame concludes with a postamble, identified by a postamble sequence detector, confirming the end of the transmission. After processing Msg2, the device is capable of computing the timing for the next expected Msg0. Figure 8(A) outlines the process undertaken by the Ambient IoT device to generate and transmit Msg3 (800A), which is the uplink message used to send vital information such as the device type, device ID, and other operational data back to the reader. This transmission is initiated only after the device has successfully received Msg2 from the reader, confirming its allocated time-frequency resources. Msg3 serves as a key stage in the communication cycle, enabling the device to participate in the network by sending its unique identity and application data. The process begins with the formation of the Layer 2 information block, which consists of control information and user data. Specifically, fields such as the Random ID (assigned earlier), Device Type, Device ID, and any optional payload (e.g., sensor readings or tracking information) are combined. This L2 data undergoes CRC attachment to ensure integrity during transmission, followed by line coding to transform the bitstream into a format suitable for modulation. Next, the encoded signal is passed through a modulation block that supports low-power schemes like OOK, BPSK, or BFSK methods compatible with the device’s energy-constrained architecture. Parallel to data encoding, a synchronization signal is generated to facilitate proper reception at the reader end. This includes a Start Indicator and a Clock Acquisition signal, both of which are combined to form the preamble using a dedicated preamble sequence generator. The modulated data signal, now labeled as PDRCH (Physical Device-to-Reader Channel), is then structured into a complete Msg3 frame by appending the preamble at the beginning and a postamble at the end. Zero padding may also be applied between the PDRCH and the postamble, if necessary, to align the message with NR OFDM symbol boundaries. Once fully assembled, Msg3 is transmitted by the device during the time and frequency slot assigned to it in Msg2, allowing the reader to receive the required device-specific information. Figure 8(B) represents the downstream process at the reader side (which could be a base station or user equipment acting as a relay) for receiving and decoding Msg3 (800B) from an Ambient IoT device. This step is essential to complete the uplink phase of the communication protocol and enables the reader to interpret device identity and operational data with accuracy and reliability. The reception process begins with the detection of the preamble in the incoming Msg3 signal. A preamble sequence detector identifies the Start Indicator, which marks the beginning of the frame, and utilizes the Clock Acquisition signal to align the reader’s internal timing with the incoming transmission. Following successful synchronization, the reader extracts the PDRCH signal and processes it using demodulation techniques compatible with the modulation scheme applied by the device (e.g., OOK, BPSK, or BFSK). The demodulated bitstream is then decoded, and a CRC check is performed to verify the integrity of the received message. The Layer 2 payload recovered from the PDRCH signal includes the Random ID, Device Type, Device ID, and any optional user data. An additional field for repetition may be present if redundancy is supported in the system to improve decoding robustness under low SNR conditions. The frame concludes with a postamble, which is recognized by a postamble sequence detector to confirm the end of the message. This clear demarcation of frame boundaries ensures accurate and complete reception of the device’s message. Based on the outcome of this decoding process, the reader determines whether the Msg3 has been successfully received. If successful, the reader will transmit an ACK as part of Msg4 to acknowledge proper reception. If decoding fails or the CRC check fails, a NAK is transmitted instead, prompting the device to retry in the next communication slot. The reception and processing of Msg3 allow the reader to complete the device's registration and update the communication status, which is essential for enabling robust, low-power, high-density Ambient IoT operations in a 5G or 6G environment. Figure 9(A) depicts the process by which the reader transmits Msg4 (900A), a critical downlink message that provides feedback to Ambient IoT devices following the reception and decoding of Msg3. This stage marks a fundamental element of the communication protocol, implementing a robust acknowledgment mechanism that ensures reliable message delivery within a power-constrained and interference-sensitive Ambient IoT environment. After receiving Msg3 from multiple devices simultaneously, the reader evaluates each incoming message individually by referencing the unique Random ID associated with every device. For each successfully decoded Msg3, the reader generates an ACK (Acknowledgment) signal tagged to that device’s Random ID. Conversely, if Msg3 for a particular device could not be decoded correctly due to channel errors, insufficient energy, or timing mismatch the reader generates a NAK (Negative Acknowledgment) for that device. The reader then compiles a Layer 2 (L2) control and data block, comprising a list of Random IDs along with their corresponding ACK / NAK status. The combined control information undergoes CRC attachment to ensure integrity, followed by line coding to prepare the bitstream for modulation. The message is then modulated using ultra-low power schemes such as OOK-1 or OOK-4 combined with OFDM to ensure compatibility with the devices' energy budgets. Parallel to data processing, a preamble consisting of a Start Indicator and Clock Acquisition signal is generated using a dedicated preamble sequence generator to facilitate synchronization at the device end. The fully constructed PRDCH (Physical Reader-to-Device Channel) frame containing the preamble, modulated Msg4 payload, optional padding for symbol alignment, and a postamble indicating the end of the message is then transmitted by the reader. This targeted, low-latency feedback enables each Ambient IoT device to understand the outcome of its previous uplink communication and determine the next appropriate action, thus ensuring system-wide communication efficiency. Figure 9(B) illustrates the reception and interpretation of Msg4 (900B) at the Ambient IoT device, completing the acknowledgment phase of the communication protocol. This step is critical, as it determines whether the device’s previously transmitted Msg3 was successfully received and if further action is required. Upon receiving Msg4, the device begins by detecting the preamble using its preamble sequence detector, which locates the Start Indicator and synchronizes its internal timing using the Clock Acquisition signal. Once the PRDCH frame is successfully synchronized, the device demodulates the incoming signal using the appropriate scheme (e.g., OOK-1 / OOK-4) and decodes the Layer 2 data. A CRC check is performed to validate the integrity of the decoded message. If the CRC passes, the device extracts the feedback corresponding to its own Random ID, identifying whether the status is ACK or NAK. If the device receives an ACK signal, it confirms that Msg3 was received and decoded correctly by the reader. As a result, the device does not attempt Msg1 retransmission in future slots, thereby conserving energy and closing the loop for the current communication cycle. On the other hand, if the device receives a NAK signal, it implies a failure in Msg3 delivery. Consequently, the device prepares to retransmit its information during the next available communication opportunity. This structured retry logic allows the system to maintain reliable connectivity even in dynamic or congested environments. The Msg4 frame concludes with a postamble, which is detected by the device’s postamble sequence detector to determine the end of the frame. This clean framing structure ensures accurate message boundary recognition and robust decoding. By receiving and interpreting Msg4, the device effectively completes a full transmission-feedback cycle and can adapt its subsequent communication behavior accordingly. This feedback mechanism forms the backbone of resilience and energy efficiency in Ambient IoT deployments operating over 5G / 6G networks. Figure 10(A) illustrates the enhanced method of preparing Msg1 for transmission from an Ambient IoT device to the reader using differential encoding of control information (1000A). This approach is adopted as an alternative to direct concatenation of control and data bits and is especially beneficial in environments with variable SNR (Signal-to-Noise Ratio) or where energy efficiency and decoding reliability are paramount. The process begins at the Layer 2 (L2) level, where the device aggregates its communication data, including fields such as the Random ID, Message Size, and Device Energy Status. These are part of the D2R information bits, which also include additional data or control fields as necessary for uplink transmission. Unlike standard message construction methods where control and data fields are directly appended and passed through the CRC and encoding pipeline, here the control information bits are first processed through a differential encoder. The differentially encoded control information is then combined with the remaining data bits, which together form a complete message frame. This merged signal undergoes CRC attachment for integrity protection, followed by line coding to prepare the bitstream for modulation. The resulting signal is modulated using ultra-low-power schemes like OOK, BPSK, or BFSK, suitable for backscatter-based communication and optimized for devices with limited power budgets. Concurrently, the device generates a synchronization preamble, composed of a Start Indicator and a Clock Acquisition signal, using a preamble sequence generator. This preamble ensures proper timing alignment between the device and the reader. The full Msg1 frame is then constructed by assembling the preamble, the modulated payload (PDRCH), any required padding for alignment with OFDM symbol boundaries, and a postamble, generated via a postamble sequence generator to mark the end of the frame. This method of differential encoding offers added resilience against phase and polarity shifts, which are common in low-power and noisy channels typical of Ambient IoT environments. Figure 10(B) presents the complementary process at the reader side, where Msg1 is received and the differentially encoded control information is decoded to complete the initial handshake in the Ambient IoT communication protocol (1000B). This stage is vital for accurate identification and scheduling of devices attempting to access the channel. Upon receiving Msg1, the reader begins with preamble detection, identifying the Start Indicator and using the Clock Acquisition signal for timing synchronization. The reader then demodulates the incoming PDRCH signal using the same scheme applied by the device (OOK, BPSK, or BFSK), recovering the encoded bitstream. This bitstream is passed through a decoding module, where it is split into data and control components. The control information is subjected to differential decoding, which reverses the encoding applied by the device. This decoding technique is especially effective in scenarios with channel imperfections, as it does not require an absolute reference phase, improving the robustness of control signal interpretation. In parallel, the CRC check validates the integrity of the full message, ensuring that neither the data nor control fields have been corrupted during transmission. The reader then extracts the Random ID, Message Size, and Device Energy Status from the decoded payload. These fields are used to identify the device, evaluate its readiness, and schedule it for further communication steps (e.g., Msg2). The complete Msg1 frame is concluded by recognizing the postamble, which is detected by a dedicated sequence detector to confirm the end of the message. In certain embodiment, the communication system may further comprise functional modules designed to manage timing synchronization and resource coordination between the reader and multiple ultra-low power Ambient IoT devices. These functional modules may include, but are not limited to a timing controller, a scheduling module, control logic, and a padding module, each operatively coupled to the processing unit and network interface of the reader. The timing controller may be configured to compute a timing offset (Toffset) for each device, based on synchronization information contained in the paging message (Msg0). This timing offset allows for alignment of uplink transmissions such as Msg1 and Msg3 with orthogonal frequency-division multiplexing (OFDM) symbol boundaries as defined by the NR communication framework. Symbol-level alignment improves decoding accuracy and reduces inter-symbol interference, especially in backscatter- based low-SNR conditions. The scheduling module may be configured to introduce and manage inter-message time gaps (TGap) between key message exchanges, including Msg1, Msg2, Msg3, and Msg4. These TGap intervals serve to isolate communication phases, accommodate processing delays, and absorb propagation variance, thereby ensuring consistent timing separation between reader-to-device and device-to-reader operations. In some embodiments, control logic may be provided to dynamically adjust one or more TGap durations based on system conditions. Such adjustments may be responsive to operational factors including the number of concurrently active devices, observed message collisions, processing load at the reader, or channel bandwidth availability. This adaptive timing mechanism ensures robust operation under both sparse and dense device deployment scenarios. Further, a padding module may be implemented to apply zero- padding to message frames prior to transmission. The amount of padding may be determined based on the computed Toffset value, ensuring that each message is aligned precisely with the NR frame structure. This structural alignment facilitates seamless integration with NR base station receivers and maintains the timing consistency required for proper decoding and scheduling. Collectively, these functional modules contribute to a scalable, energy-aware, and time-synchronized Ambient IoT communication architecture, supporting the claimed invention and ensuring efficient operation in real-world heterogeneous network environments. Figure 11 presents a flowchart (1100) outlining a slotted ALOHA- based random-access mechanism designed to enable Ambient IoT devices to initiate communication with a base station by transmitting Msg1. This method supports low-power, asynchronous access in dense IoT deployments, minimizing collisions and ensuring scalability and fairness in time-frequency resource allocation. The process begins when the Ambient IoT device has a pending transmission (Msg1) containing its random ID, message size, and energy status. Initially, a transmission attempt counter K is set to zero (K=0). This counter tracks the number of attempts the device makes to send Msg1 in a given access cycle and ensures it does not exceed the maximum number of retries (X), helping avoid excessive contention. The device then monitors the network to determine if the next communication slot has started. This slotted approach ensures synchronization with the base station’s communication window and avoids out-of-bound transmissions. Once a new slot begins, the device proceeds by randomly selecting a subcarrier index f within the available subcarrier range [1, Y]. This subcarrier (FSCf) is used for frequency division multiplexing, allowing simultaneous transmissions from multiple devices with reduced interference. After selecting a subcarrier, the device sends Msg1 on the chosen frequency. The frame transmission is followed by a wait period of T = 2 × TP, where TP represents the propagation delay. This duration accounts for the round-trip time required for the message to reach the base station and for the base station to respond with an acknowledgment (ACK). Following the wait period, the device checks whether an ACK has been received. If it has, the device considers the access attempt successful, terminates the process, and proceeds to await further instructions (e.g., resource grants via Msg2). If no ACK is received, it indicates either a failed transmission or a collision with another device. In the event of no ACK, the retry counter K is incremented by one. The device then checks whether K has exceeded the maximum number of allowed attempts (X). If so, the device aborts the current access attempt and waits for the next paging opportunity (Msg0) before trying again. If K is still within the allowed retry window, the device proceeds to calculate a backoff time before the next attempt. The backoff is determined by selecting a random number t in the range [1, X-K], and the device waits for a period T = t × T₁_min, where T₁_min is the minimum duration required to send Msg1. This randomized wait ensures that retries are distributed across time, reducing the chances of repeated collisions among devices competing for the same time slot. Once the backoff period concludes, the device loops back to the slot- checking stage and repeats the process if required. This randomized slotted ALOHA mechanism effectively supports concurrent access attempts from a large number of ultra-low power Ambient IoT devices, which may be operating under strict energy and timing constraints. This random-access mechanism is tightly integrated with the broader Ambient IoT system architecture. Devices rely on energy harvesting (e.g., via continuous wave signals from the base station or user equipment) and may determine whether to proceed with access based on their available energy level. If energy is insufficient, the device may enter a sleep mode until it has recharged, thus optimizing power consumption. Additionally, devices maintain essential identifiers such as device ID and message size in non-volatile memory (e.g., EEPROM) and use baseband logic units comprising decoders, encoders, and controllers to manage modulation, timing, and state transitions. The Msg1 frame is typically modulated by backscatter using schemes such as ASK, PSK, or FSK, depending on system parameters like data rate, power efficiency, and channel conditions. 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: method for enabling wireless communication between a transceiver and a plurality of ultra-low power, battery-less devices, the method comprising: transmitting a carrier wave (CW) signal to facilitate radiofrequency (RF) energy harvesting by the devices; broadcasting a paging signal to initiate device discovery and time synchronization; receiving random access messages from the devices, each random- access message including a randomly generated identifier, energy status, and message size; allocating frequency and time domain communication resources to a subset of the devices based on received information and available bandwidth; transmitting a resource allocation message to the subset of devices specifying the assigned subcarriers and time slots; receiving uplink messages from the devices using the allocated resources, each uplink message comprising device-specific identification and data; and transmitting a response message to each of the devices comprising an acknowledgment (ACK) or negative acknowledgment (NAK) based on decoding success,wherein a device receiving an ACK discontinues further communication attempts, and a device receiving a NAK reattempts transmission during a subsequent communication cycle.

2. The method as claimed in claim 1, further comprising: computing a timing offset (Toffset) at each device based on synchronization information contained in the paging signal, wherein the Toffset, the time interval from the end of the R2D transmission triggering random access to the starting time of the first Msg1 time domain resource, is used to align uplink transmissions with orthogonal frequency-division multiplexing (OFDM) symbol boundaries; introducing inter-message time gaps (TGap) between consecutive message exchanges, including Msg1, Msg2, Msg3, and Msg4, to establish distinct reception windows at the transceiver; dynamically adjusting the duration of TGap based on one or more system parameters selected from the number of active devices, observed collision rates, processing delays, or available communication resources; and applying padding after PRDCH or PDRCH and before postamble to message frames to ensure symbol-aligned transmission within the NR frame structure.

3. The method as claimed in claim 1, wherein the paging signal, random access message, scheduling message, uplink message, andacknowledgment message respectively correspond to Msg0, Msg1, Msg2, Msg3, and Msg4.

4. The method as claimed in claim 1, wherein the random-access messages are transmitted using a slotted Aloha-based access protocol within a predefined time window.

5. The method as claimed in claim 1, wherein the resource allocation comprises assigning frequency domain resources including subcarriers and time domain resources including orthogonal frequency-division multiplexing (OFDM) time slots.

6. The method as claimed in claim 1, wherein the paging signal and CW signal are transmitted sequentially or concurrently during each communication cycle.

7. The method as claimed in claim 1, wherein the transmitted messages include a preamble comprising a start indicator and synchronization signal, and a postamble indicating the frame boundary.

8. The method as claimed in claim 1, further comprising generating physical layer signals by: forming Layer 2 payload data; applying a cyclic redundancy check (CRC); encoding the data using a line coding scheme; and modulating the encoded signal for transmission.

9. The method as claimed in claim 1, wherein control and system information are encoded using differential encoding prior to modulation.

10. A system for facilitating wireless communication with a plurality of ultra-low power, battery-less devices, the system comprising: a network interface configured to: transmit a carrier wave (CW) signal for RF energy harvesting; broadcast a paging signal to initiate device discovery; receive random access messages from the devices; transmit resource scheduling information to selected devices; receive uplink data messages from the devices; and transmit acknowledgment messages in response to the uplink data; a processor operably coupled to the network interface and configured to: decode received random access messages; allocate subcarriers and time slots to eligible devices; generate and transmit scheduling and feedback messages; and process received uplink messages to extract device identity and data content.

11. The system as claimed in claim 10, further comprising:a timing controller configured to compute a timing offset (Toffset) for each device based on synchronization information contained in the paging signal, wherein the Toffset, the time interval from the end of the R2D transmission triggering random access to the starting time of the first Msg1 time domain resource, is used to align uplink transmissions with orthogonal frequency-division multiplexing (OFDM) symbol boundaries; a scheduling module configured to introduce inter-message time gaps (TGap) between consecutive message exchanges, including Msg1, Msg2, Msg3, and Msg4, to establish distinct reception windows at the transceiver; control logic configured to dynamically adjust the TGap duration based on one or more system parameters selected from the number of active devices, observed collision rates, processing delays, or available communication resources; and a padding module configured to apply padding to ensure symbol- aligned transmission within the NR frame structure.

12. The system as claimed in claim 10, wherein control and system information are encoded using differential encoding prior to modulation.

13. The system as claimed in claim 10, wherein the processor comprises a scheduler configured to dynamically prioritize devices based on energy level, message size, or contention level.

14. The system as claimed in claim 10, wherein the system further comprises: a memory configured to store resource allocation states, message templates, and device metadata; and a modulation controller configured to generate physical layer signals for downlink (PRDCH) and uplink (PDRCH) communication.

15. The system as claimed in claim 10, wherein the processor is configured to generate Msg2 and Msg4 messages, and to decode Msg3 payloads to extract device identification and uplink data.

16. The system as claimed in claim 10, wherein the network interface comprises multiple antenna elements configured to transmit steered beams at different frequencies to support spatially diverse communication with multiple devices.

17. The system as claimed in claim 10, wherein the system is operable as a base station or as a user equipment (UE) functioning as a relay between the devices and a core network.

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