Methods and apparatus for ambient internet-of-things (IOT) device configuration

Abstract

In accordance with implementations, an Internet-of-Things (IoT) device receives, from a reader, a contention-based access configuration comprising information for a plurality of radio-frequency (RF) channels that can be used by the IoT device for uplink communication with the reader. The IoT device selects a first RF channel from the plurality of RF channels. The IoT device sends a contention-access response to the reader using the first RF channel. The contention-access response indicates a device identifier of the IoT device. The IoT device receives, from the reader, a contention-access acknowledgment indicating the device identifier.

Description

METHODS AND APPARATUS FOR AMBIENT INTERNET-OF-THINGS (IOT) DEVICE CONFIGURATIONPRIORITY CLAIM AND CROSS-REFERENCE

[0001] This patent application claims priority to U.S. Provisional Application No. 63 / 574,549, filed on April 4, 2024, and entitled “METHODS AND APPARATUS FOR AMBIENT INTERNET-OF-THINGS (IOT) DEVICE CONFIGURATION,” which is hereby incorporated by reference herein as if reproduced in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates generally to internet-of-things devices and methods, and in particular embodiments, to a method and apparatus for ambient internet-of-things device configuration.BACKGROUND

[0003] Within the framework of Release 19, 3GPP is studying a new device, so- called Ambient Internet-of-Things (AIoT) device, aiming at expanding the 5G New-Radio device ecosystem. In comparison with a conventional 3GPP cellular loT device (for example, a Narrowband loT device), Ambient loT devices are not powered by traditional batteries, and have ultra-low complexity and power consumption. Such devices are characterized by their small form factor and capability to harvest energy sources from the environment such as radio electromagnetic waves, solar or light, kinetic or vibration, wind, thermal, among others. Additionally, these devices may be equipped with limited energy storage (e.g., supercapacitors) for storing electric energy harvested from the ambient energy sources. As a result, high maintenance costs and safety hazards due to manually changing or recharging batteries on individual loT devices can be eliminated, leading to an eco-friendly and sustainable technology of the future, reducing the carbon footprint of today’s supply chain.SUMMARY

[0004] Technical advantages are generally achieved, by embodiments of this disclosure which describe a method and apparatus for ambient internet-of-things device configuration.

[0005] In accordance with implementations, an Internet-of-Things (loT) device receives, from a reader, a contention-based access configuration comprising information for a plurality of radio-frequency (RF) channels that can be used by the loT device foruplink communication with the reader. The loT device selects a first RF channel from the plurality of RF channels. The loT device sends a contention-access response to the reader using the first RF channel. The contention-access response indicates a device identifier of the loT device. The loT device receives, from the reader, a contention-access acknowledgment indicating the device identifier.

[0006] In some implementations, the contention-based access configuration indicates an initial center frequency, a number of RF channels, and frequency resources in each of the plurality of RF channels.

[0007] In some implementations, the contention-based access configuration further indicates a carrier-wave frequency, and the carrier-wave frequency is within an uplink band used by the loT device for the uplink communication with the reader.

[0008] In some implementations, the contention-based access configuration further indicates a carrier-wave frequency, and the carrier-wave frequency is within a downlink band used by the loT device for downlink communication with the reader.

[0009] In some implementations, the contention-based access configuration further indicates availability of the plurality of RF channels and a device categon .

[0010] In some implementations, the contention-based access configuration includes a bitmap indicating the availability of the plurality of RF channels.

[0011] In some implementations, the contention-based access configuration includes a list indicating the availability of the plurality of RF channels.

[0012] In some implementations, the reader includes a 5th generation (5G) cellular base station, an intermediate node, an assisting node, or a user equipment (UE).

[0013] In some implementations, the contention-based access configuration further indicates a collision avoidance parameter.

[0014] In some implementations, after the selecting the first RF channel, the loT device selects a random number between 0 and 1, the sending the contention-access response includes sending the contention-access response in response to determining, by the loT device, that the random number is less than or equal to the collision avoidance parameter.

[0015] In some implementations, the loT device receives, from the reader, a message indicating the device identifier and a center frequency of a second RF channel, and sends, to the reader using the second RF channel, a response to the message.

[0016] In some implementations, the first RF channel is same as the second RF channel, or the first RF channel is different from the second RF channel.

[0017] In some implementations, the plurality of RF channels are within a new radio (NR) guard band or an NR inner band.

[0018] In accordance w ith implementations, a reader scans a plurality of radiofrequency (RF) channels, determines qualities of the plurality of RF channels, and determines whether to keep or replace an assigned RF channel based on determining if at least one RF channel of the plurality of RF channels has a better quality than the assigned RF channel.

[0019] In some implementations, in response to determining that at least one of the plurality of RF channels has the better quality than the assigned RF channel, the reader replaces the assigned RF channel with a highest quality RF channel from the plurality of RF channels.

[0020] In some implementations, in response to determining that none of the plurality of RF channels has the better quality than the assigned RF channel, the reader keeps the assigned RF channel.

[0021] In some implementations, the plurality of RF channels are within a new radio (NR) guard band or an NR inner band.

[0022] In some implementations, the plurality of RF channels are used for downlink communication with Internet-of-Things (loT) devices.

[0023] In accordance with implementations, a reader communicates with Internet- of-Things (loT) devices using a plurality of assigned radio-frequency (RF) channels for uplink communication with the loT devices, and determines whether at least one device- to-device collision is detected in the plurality of assigned RF.

[0024] In some implementations, in response to determining that the at least one device-to-device collision is detected, the reader increases a total allocated spectrum for the uplink communication with the loT devices, generates a plurality of updated RF channels for the uplink communication with the loT devices based on the total allocated spectrum, determines a number of the updated RF channels, assigns the plurality of updated RF channels, and transmits, to the loT devices, a contention-based access configuration indicating the number of the updated RF channels.

[0025] In some implementations, in response to determining that no device-to- device collisions are detected, the reader determines whether at least one of the plurality of assigned RF channels is unused and removes unused RF channels from the plurality of assigned RF channels.

[0026] In some implementations, the plurality of assigned RF channels are within a new radio (NR) guard band or an NR inner band.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the follow ing descriptions taken in conjunction with the accompanying drawings, in which:

[0028] FIG. t shows example AIoT network topologies, in accordance with some implementations;

[0029] FIG. 2 shows example baseband waveforms of different encoding schemes, in accordance w ith some implementations;

[0030] FIG. 3 shows an example baseband waveform of pulse-interval encoding, in accordance w ith some implementations;

[0031] FIG. 4 shows example AIoT operation modes, in accordance with some implementations;

[0032] FIG. 5 shows an example of dynamic channelization for device-to-reader transmission during a New Radio in-band operation mode, in accordance with some implementations;

[0033] FIG. 6 shows an example of dynamic channelization for device-to-reader transmission during a combined New Radio in-band and guard-band operation mode, in accordance w ith some implementations;

[0034] FIG. 7 shows an example of dynamic channelization for reader-to-device transmission during a New Radio in-band operation mode, in accordance with some implementations;

[0035] FIG- 8 shows an example of dynamic channelization for reader-to-device transmission during a combined New Radio in-band and guard-band operation mode, in accordance with some implementations;

[0036] FIG. 9 shows a flow7chart of a method for autonomous Dynamic channel selection performed by a wireless system, in accordance with some implementations;

[0037] FIG. 10 shows an example of AIoT indoor deployment scenario, in accordance with some implementations;

[0038] FIG. 11A shows sequence diagrams of AIoT contention-based and contention-free access methods, in accordance with some implementations;

[0039] FIG. 11B shows a flow chart of a method for AIoT contention-based access, in accordance with some implementations;

[0040] FIG. 12 shows a flow7chart of a method for adaptive AIoT spectrum configuration for device-to-reader transmission, in accordance with some implementations;

[0041] FIG. 13A shows sequence diagrams of a contention-based channel access method w ith the p-persistent Aloha protocol and a contention-free access method, in accordance with some implementations;

[0042] FIG. 13B shows a flow chart of a method for contention-based channel access method with the p-persistent Aloha protocol, in accordance with some implementations;

[0043] FIG. 14 shows a flow chart of a p-persistent algorithm, in accordance ith some implementations;

[0044] FIG. 15 shows a flow chart of a p-persistent algorithm, in accordance with some implementations;

[0045] FIG. 16 shows an example of contention-based channel access on NR timefrequency resource grid, in accordance with some implementations;

[0046] FIG. 17 shows an example of contention-based channel access on NR timefrequency resource grid, in accordance with some implementations;

[0047] FIG. 18 illustrates an example communications system, in accordance with some implementations;

[0048] FIG. 19 illustrates an example communication system, in accordance with some implementations;

[0049] FIGS. 20A and 20B illustrate example devices, in accordance with some implementations; and

[0050] FIG. 21 shows a block diagram of a computing system, in accordance with some implementations.

[0051] Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0052] The making and using of embodiments of this disclosure are discussed in detail below. It should be appreciated, however, that the concepts disclosed herein can be embodied in a wide variety of specific contexts, and that the specific embodiments discussed herein are merely illustrative and do not serve to limit the scope of the claims. Further, it should be understood that various changes, substitutions and alterations can be made herein w ithout departing from the spirit and scope of this disclosure as defined by the appended claims.

[0053] The present disclosure relates to methods and apparatus for configuring Ambient Internet-of-Things (AIoT) devices in wireless communication systems. The methods involve a contention-based access procedure between AIoT devices and readers, where readers allocate radio-frequency (RF) channels for device-to-readercommunication through dynamic or static channelization. In the dynamic channelization approach, the reader divides allocated spectrum into multiple orthogonal RF channels through frequency-division multiplexing and provides configuration parameters to AIoT devices including initial center frequency, number of RF channels, frequency resources per channel, and anti-contention protocol parameters such as p-persistent Aloha parameters.

[0054] In some embodiments, the AIoT devices receive the channelization configuration from readers, select an RF channel, and communicate using the selected channel through a contention-based access procedure that implements anti-contention protocols like p-persistent Aloha or slotted Aloha with Q -algorithm. In the p-persistent Aloha implementation, devices randomly generate a number between 0 and 1 and only transmit if this number is less than or equal to a reader-configured persistence parameter. The present disclosure also includes methods for readers to adaptively adjust spectrum allocation based on detected device collisions by increasing total spectrum and number of RF channels when collisions occur, or removing unused channels when no collisions are detected.

[0055] Embodiments of the present disclosure provide various advantages. Various embodiments provide advantages in managing massive loT device deployments by eliminating device-to-device collisions through a combination of dynamic channelization and anti-contention protocols. The dynamic spectrum allocation allows readers to efficiently adapt to varying device populations and traffic demands by increasing available RF channels when collisions occur and removing unused channels when traffic is low. This adaptive approach, combined with the ability to implement different anticontention protocols, enables efficient spectrum utilization while maintaining reliable communication even in dense loT deployments.

[0056] Various embodiments support multiple operation modes (NR in-band, guard-band, and standalone) and are compatible with existing 5G infrastructure providing cost-effective implementation options for network operators. The ability to support both primitive and enhanced AIoT devices through various network topologies (direct to gNodeB, via intermediate or assisting nodes, or through UEs) enables widespread deployment while maintaining efficient spectrum usage. Additionally, the autonomous channel selection capability allows readers to optimize their channel assignments based on real-time quality measurements, improving overall system reliability and performance.

[0057] Ambient Internet-of-Things (AIoT) devices, also known as ambient intelligence or ambient computing devices, are a subset of loT devices that operate in the background, using sensors, data analytics, and connectivity to create intelligent andadaptive environments. These devices are often unobtrusive, embedded in our surroundings, and provide a continuous flow of data that can be analyzed and acted upon to improve various aspects of our lives. AIoT devices are characterized by their ability to collect data from their surroundings, process it, and respond autonomously to changing conditions, making them well-suited for a variety of applications where automation and adaptability are important.

[0058] Unlike 5G New Radio, AIoT transmission technology is not based on OFDM due to ultra-low complexity and power consumption requirements. 3GPP differentiates between primitive and enhanced Ambient loT devices in the Release-19 study scope as presented in Table 1. The former, which is referred to as Device 1, is not expected to be equipped w ith an oscillator to generate a local carrier frequency. Consequently, such a device purely communicates based on the principle of backscattering and is unable to amplify uplink (and downlink) signals. Device 1 relies on an external carrier (or continuous) wave, which is a periodic sinusoidal wave that is continuous in time, without changing its amplitude, frequency or phase, and it carries no information. The carrier wave is used by Device 1 to modulate its data before it is reflected (or scattered) back. In some embodiments, the carrier wave can be generated and transmitted by an AIoT- enabled 5G New-Radio cellular base station (i.e., gNode B), User Equipment, relay, repeater, or the like. In an embodiment, Device 1 has electrical energy storage (e.g., a capacitor) and its peak power consumption is approximately 1 nW.

[0059] As compared with the primitive AIoT devices, the enhanced AIoT device’s peak power consumption is higher but does not exceed a few hundred microwatts and is equipped with active radio-frequency components that are used to amplify uplink and / or downlink signals. Such devices also have electrical energy storage (e.g., a capacitor). In 3GPP, the enhanced AIoT device is further categorized into Device 2a and Device 2b. The main difference between these two enhanced AIoT devices is in the functionality of uplink transmission. Device 2b can internally generate a local RF carrier for its uplink transmission, while Device 2a depends on backscattering an externally provided carrier wave. In some embodiments, an enhanced device may combine the functionality of both Device 2a and Device 2b and may have the option to communicate using either backscattering or internal uplink signal generation. In such embodiments, the network could configure individual enhanced AIoT devices regarding which communication option to use depending on use cases.Table 1: 3GPP Ambient loT Device Types

[0060] FIG. 1 shows example AIoT network topologies, in accordance with some implementations. An AIoT device too, which may be a primitive (e.g., Device 1) or enhanced (e.g., Device 2a or DeGee 2b) deGee can connect either directly to a gNode B 108 or indirectly via an intermediate node 112, assisting node 114, or User Equipment(UE) 116 according to different topologies. According to a topology 100A (gNode B «-> AIoT Device), the AIoT Device 110 is directly connected to a gNode B 108. According to a topology 100B (gNode B Intermediate Node AIoT Device), the AIoT Device 110 is connected to gNode B 108 through an intermediate node 112. According to a topology 100C (gNode B Assisting Node AIoT Device gNode B), the AIoT Device 110 is connected to a gNode B 108 directly as well as through an assisting node 114. According to a topology 100D (UE AIoT DeGee), the AIoT Device 110 is directly connected to the UE 116. In topologies 100A-C, the gNode B 108 is connected to an AIoT server 102 through a data network 104 and a 5G core network 106. Various embodiments described herein is applicable to all the aforementioned topologies.

[0061] Each AIoT network topology can support one or more deployment scenarios as presented in Table 2.Table 2: Ambient loT Deployment Scenarios and Network Topologies

[0062] AIoT technology enables massive deployment of battery-free and low-cost loT devices, which opens a whole new world of use cases and provides added value across the entire supply chain. To date, 3GPP groups AIoT use cases into four broad categories, viz. Inventory, Sensor, Positioning, and Command. The Inventory and Command use cases are selected for studies in Release 19.

[0063] The following nomenclature is used throughout the disclosure. Ambient loT reader is denoted as “R”. In Topology 100A, “R” can represent an AIoT-enabled base station, a gNode B, a Transmission Reception Point (TRxP), an eNode B, or an access point. In Topology 100B, “R” can represent an intermediate node, User Equipment (UE), a relay, a repeater, or an Integrated Access Backhaul (IAB). “D” denotes an AIoT device, which can be Device 1, Device 2a or Device 2b. When ambiguity arises, the full terminology is explicitly used.

[0064] In general, raw binary data is encoded as a continuous stream of bits suitable for transmission over the air prior to digital modulation. Such data encoding is line encoding, which is widely used to convert baseband signals in binary format (i.e., a sequence of ones and zeros) to a specific baseband waveform according to some defined mapping rules. The line encoding schemes can be broadly categorized into level encoding and transition encoding techniques. The former represents a binary bit with their voltage level (e.g., a positive voltage level for the binary 1 and a corresponding negative voltage level for the binary o). In the latter, the binary bit is represented by a change in voltage levels. Level encoding techniques include nonreturn to zero (NRZ) and return to zero (RZ), w hich are independent of the previous binary’ bit. On the other hand, transition encoding techniques can be dependent on the previous binary bit transmission, which are more robust in comparison w ith the level encoding.

[0065] Manchester, FMo, Miller, and Pulse-Interval Encoding (PIE) among others are examples of transition encoding schemes. FIG. 2 shows example baseband waveforms of Manchester, FMo and Miller encoding schemes, in accordance w ith some implementations. In particular, a waveform 202 represents a binary7data, a waveform 204A represents Manchester encoding of the binary7data, a waveform 204 B representsFMo encoding of the binary7data, and a waveform 204C represents Miller encoding of the binary data. FIG. 3 shows an example baseband waveform of pulse-interval encoding, in accordance w ith some implementations. In particular, a waveform 302 represents a binary data and a waveform 304 represents PIE of the binary data. A brief description of each of these encoding schemes is presented in T able 3.Table 3: Summary of Manchester, FMo, Miller and PIE Encoding Schemes

[0066] In UHF RFID technology, Manchester and Pulse-Interval Encoding are two popular choices applied to encode raw7binary data for transmission from an interrogator(or reader) to a tag. In the opposite direction, FMo, Miller, and Pulse Positioning Encoding are among the encoding schemes employed.AMBIENT IOT OPERATION MODES

[0067] FIG. 4 shows example AIoT operation modes, in accordance with some implementations. As stated in the 3GPP study item description, AIoT technology operates in the FDD mode, w ith a pair of frequency bands, one for uplink and another one for downlink transmission. The uplink frequencies 402U and downlink frequencies 402D are orthogonal and are separated by a duplex spacing 404 to reduce selfinterference between transmission and reception. The AIoT technology uses licensed FDD spectrum, which includes New-Radio spectrum in Frequency Range 1 or FR1 (i.e., 410 MHz to 7125 MHz) and non-New Radio spectrum (such as FDD spectrum previously used for GSM). The whole FRt licensed spectrum is typically divided into a number of frequency (or operating) bands. An operating band comprises the uplink frequency range (fuL.L ~ fuL,n) and the downlink frequency range (JDL,L- fDL.n)- Each operating band may be further divided into several chunks or blocks, where each is licensed to a particular mobile network operator for exclusive use. For example, the uplink band 402U may be divided into a block 406U licensed to a mobile network operator X and a block 408U licensed to a mobile network operator Y, and the downlink band 402D may be divided into a block 406D licensed to the mobile network operator X and a block 408D licensed to the mobile network operator Y.

[0068] For the AIoT technology, operating bands located in the lower frequency (for example, below 2 GHz) of FRt are preferred over the higher ones due to lower path loss, resulting in larger coverage (or longer communication distances). In some embodiments, FDD operating bands, which offer a good balance between antenna size and path loss, are of interest to AIoT devices. In addition, such an FDD band should be available worldwide in order to ensure interoperability for global use of AIoT devices and should suit indoor and outdoor AIoT deployment scenarios (see Table 2). In an embodiment, New Radio n8 is one exemplary FDD operating band. It is important to note that the AIoT technology is not limited to a particular operating band but is capable of supporting multiple bands depending on implementation.

[0069] In some embodiments, for a New-Radio FDD operating band, the AIoT- enabled 5G base station can allocate a chunk of the frequency resources inside the New- Radio channel bandwidth for AIoT use, which is referred to as the New-Radio in-band operation mode 410A as shown in FIG. 4. For example, a chunk 412U of the block 406U and a chunk 412D of the block 406D may be allocated for AIoT use in the New-Radio in- band operation mode 410A.

[0070] In other embodiments, for a New-Radio FDD operating band, the AIoT- enabled 5G base station can allocate guard bands on either side of the New-Radio channel edges, which is referred to as the New-Radio guard-band operation mode 410B as show n in FIG. 4. For example, guard bands 414U and 414D may be allocated for AIoT use in the New-Radio guard-band operation mode 410B.

[0071] In yet other embodiments when the AIoT technology does not coexist with the New Radio network, it may operate independently using non-New Radio operating bands, which can be refarmed to AIoT from prior cellular technology (e.g., GSM). Such an AIoT system operation mode may be referred to as the standalone operation mode 410C as show n in FIG. 4. For example, bands 416U and 416FD may be allocated for AIoT use in the standalone operation mode 410C.AMBIENT IOT SPECTRUM CHANNELIZATION CONFIGURATIONDynamic Channelization

[0072] In the following, the description and drawings assume the NR in-band operation mode 410A (see FIG. 4). However, they are also applicable to the NR guardband operation mode 410B and the standalone operation mode 410C (see FIG. 4).

[0073] FIG. 5 shows an example of dynamic channelization for device-to-reader transmission during a New- Radio in-band operation mode, in accordance with some implementations. For the NR in-band AIoT device-to-reader transmission, a reader belonging to a mobile network operator (e.g., Operator X) dynamically allocates a chunk 504 of the frequency resources (denoted as BD2R s) inside the uplink New-Radio channel bandwidth 502, which is in turn divided into a number of relatively narrow' orthogonal radio-frequency physical channels 506 through the use of Frequency-Division Multiplexing, each with spacing of BD2R a. Each RF channel 506 is defined by an uplink carrier frequency in the FDD uplink frequency range. The total number of device-to- reader RF channels ND2Ris given by Equation (1)where ND2Ris the number of AIoT D2R RF channels 506,BD2R sis the total spectrum allocated by the reader for AIoT D2R transmission, BD2R,Ois the frequency resources (or bandwidth) per RF channel 506, which is equal to the D2R transmission bandwidth BD2R tplus guard subcarriers / bands BD2R gon either side of the RF channel edges, that is, BD2R o= BD2R t+ 2BD2R g, andBD2R tis the frequency resources used for transmission of Ambient loT messages / packets from the device to the reader. The relationship between the aforementioned terms can be expressed as an inequality: BD2R s> BD2R o> BD2R t.

[0074] In some embodiments, the values of BD2R sand BD2R oare not constant. In such embodiments, the reader can dynamically configure BD2R sto match the population size of AIoT devices within its coverage area, and configure BD2Rr0according to the data rate requirement needed by different AIoT devices, which support different use cases. The achievable bit rate is proportional to BD2R o, modulation scheme, and SNR (Signal- to-Noise Ratio). The reader can configure BD2R oto fulfil the spectral efficiency of the selected modulation scheme. For example, non-coherent ASK modulation requires BD2R othat is twice the binary bit rate and is often described as having spectral efficiency of 0.5 bits / second / Hertz.

[0075] In the case of New-Radio in-band operation, the frequency location of AIoT spectrum within the NR channel is not fixed. Accordingly, the AIoT spectrum can be located anywhere within the NR channel, allowing efficient spectrum sharing with the New Radio technology.

[0076] In some embodiments, for co-existence with ew Radio technology, the total AIoT spectrum BD2R scan be expressed as an integral multiple of New-Radio Physical Resource Blocks (PRBs), such that each PRB consists of 12 consecutive subcarriers in the frequency domain and the bandwidth occupies by a single PRB depends upon the New- Radio subcarrier spacing. Similarly, the D2R channel bandwidth BD2R ocan be expressed as an integral multiple of PRBs even though it is not necessary. The minimum D2R channel bandwidth BD2R ois assumed to be one PRB.

[0077] Each D2R RF channel 506 is denoted by CD2R nand is defined by an uplink center (carrier) frequency fD2R n, where n G {0, ... , ND2R- 1}. The RF channel CD2R ;0represents the lowest RF channel number with the lowest center frequency fD2R,- Given the center frequency of the first RF channel and assume the bandwidth of each RF channel BD2R o) is the same, the center frequency of the nth RF channel can be obtained as fo2R,n=fo2R,0 + BD2R,OX U’ n 6 {0, ... , ND2R- 1} Equation (2) w here fD2R 0and BD2R,Oare expressed in megahertz.

[0078] It is noted that dynamic channelization is not limited to NR in-band, guardband and standalone operation modes, but it can include combined (or hybrid) New- Radio in-band and guard-band operation. Not only does the allotted Ambient loT (AIoT) spectrum include a subset of New-Radio channel bandwidth, but also the guard-band on the right channel edge as illustrated in FIG. 6 as an example. The AIoT spectrum can be partitioned in the same way as in the New-Radio In-band case described above w ith reference to FIG. 5. In some embodiments, a reader belonging to a mobile network operator (e.g., Operator X) dynamically allocates a chunk 604 of the frequency resources(denoted as BD2R s') inside the uplink New-Radio channel bandw idth 602, which is in turn divided into a number of relatively narrow orthogonal radio-frequency physical channels 606 through the use of Frequency-Division Multiplexing, each with spacing of BD R ll.

[0079] FIG. 7 shows an example of dynamic channelization for reader-to-device transmission during a New Radio in-band operation mode, in accordance with some implementations.

[0080] For the AIoT reader-to-device transmission, a mobile network operator (e.g., Operator X) determines the amount of frequency resources inside the downlink New- Radio channel bandw idth 702 reserved for AIoT devices, which depends on the dimension of an AIoT network, comprising multiple readers. In order to support asymmetric traffic between reader-to-device and vice versa, the amount of reserved spectrum for reader-to-device can be different from the device-to-reader one.

[0081] In some embodiments, a reader belonging to a mobile network operator (e.g., Operator X) dynamically allocates a chunk 704 of the frequency resources (denoted as BR2D S) inside the downlink New-Radio channel bandwidth 702, which is in turn divided into a number of relatively narrow orthogonal radio-frequency physical channels 706 through the use of Frequency-Division Multiplexing, each with spacing of BR2D o. The total number of reader-to-device RF channels NR2Dis given byNR2D =Equation (3)Where NR2Dis the number of AIoT R2D RF channels 706,BR2D,Sis the total spectrum allocated for AIoT R2D transmission,BR2D,O is the frequency resources (or bandwidth) per RF channel 706 which is equal to the R2D transmission bandwidth BR2D tplus guard subcarriers / bands BR2D gon either side of the RF channel edges, that is BR2D o= BR2D t+ 2BR2D g, andBR2D,tis the frequency resources used for transmission of Ambient loT messages / packets from the reader to the device. The relationship between the aforementioned terms can be expressed as an inequality: BR2D s> BR2D>0> BR2D t.

[0082] Each R2D RF channel 706 is denoted by CR2D nand is defined by a downlink carrier frequency in the FDD downlink frequency fR2D,n, where n G {0, ... , NR2D- 1}. The RF channel CR2D 0represents the lowest RF channel number with the lowest center frequency fR2D,0- Given the center frequency of the first RF channel and assume the bandwidth of each RF channel is the same, the center frequency of the next higher RF channels can be obtained as fR2D,n — fR2D,o + BR2D,0x n, n G {0, ... , NR2D— 1} Equation (4) where fR2Di0and BR2D oare expressed in megahertz.

[0083] It is noted that dynamic channelization is not limited to NR in-band, guardband and standalone operation modes, but it can include combined (or hybrid) New- Radio in-band and guard-band operation. Not only does the allotted Ambient loT spectrum include a subset of New-Radio channel bandw idth, but also the guard-band on the right channel edge as illustrated in FIG. 8 as an example. The AIoT spectrum can be partitioned in the same way as in the New-Radio In-band case described above w ith reference to FIG. 7. In some embodiments, a reader belonging to a mobile network operator (e.g., Operator X) dynamically allocates a chunk 804 of the frequency resources (denoted as BR2D s) inside the downlink New-Radio channel bandwidth 802, which is in turn divided into a number of relatively narrow orthogonal radio-frequency physical channels 806 through the use of Frequency-Division Multiplexing, each with spacing of BR2D,O -

[0084] Unlike the device-to-reader transmission, the reader-to-device transmission can be based on the OFDM transmission technique because an AIoT reader can be realized by reusing existing New-Radio gNode B or UEs. In such embodiments, coexistence of AIoT with the New Radio technology (in particular, New-Radio in-band and guard-band operation modes) can be supported without the need of additional hardware components, reducing Capital Expenditures (CAPEX).

[0085] In order to seamlessly co-exist with New Radio, the total AIoT spectrum BR2D sand the RF channel bandwidth BR2D ocan be expressed as an integral multiple of New-Radio PRBs (Physical Resource Blocks), such that each PRB consists of 12 consecutive subcarriers in the frequency domain and the bandwidth occupies by a single PRB depends upon the New-Radio subcarrier spacing. As a result, the guard subcarriers / bands in BR2D oare not needed provided OFDM-based transmission is employed, resulting in higher spectrum efficiency, which means that BR2D o- BR2D t. For standalone operation, the guard band may be needed.

[0086] In an AIoT system, each reader is assigned with an RF channel from CR2D 0to CR2D,NR2D-I - In some embodiments, the reader is assigned with more than one RF channel, depending upon the population of devices within its radio coverage area and AIoT use-case data rate requirements. In one embodiment, network -controlled channel selection may be used for the RF channel assignment. In such embodiment, the New- Radio access network allocates each reader in the loT system an orthogonal RF channel. In another embodiment, autonomous dynamic channel selection may be used for the RF channel assignment. In such embodiment, the network-controlled channel selection is improved by replacing the network assigned channel by a better channel if it is found. Each reader autonomously performs a scan of all the R2D RF channels prior to selectingthe RF channel w ith the best quality (or the one w ith the least interference). If the number of corrupted R2D messages is increasing, then the reader would deduce that the channel condition is deteriorating. Consequently, the reader would automatically search for a new R2D RF channel using the autonomous dynamic channel selection approach.

[0087] FIG. 9 shows a flow’ chart of a method 900 for an autonomous dynamic channel selection performed by a reader, in accordance with some implementations. Although shown in a particular sequence, it should be appreciated that the steps of the method 900 may be performed in any suitable sequence. The method 900 starts with initializing various parameters such as BR2D s, BR2D 0, BR2D t,n in step 902. In step 904, the reader scans an RF channel fR2Din. In step 906, the reader determines a quality of the RF channel fR2Dtn. In step 908, the reader determines whether scanning of all RF channels is completed. In response to determine at step 908 that scanning of all RF channels is not completed, the method 900 proceeds to step 910. In step 910, the reader increments the parameter n by 1 and selects the next RF channel. After performing step 910, the method 900 proceeds back to step 904. In some embodiments, steps 904-910 are repeated one or more times until the reader determines that scanning of all RF channels is completed.

[0088] In response to determine at step 908 that scanning of all RF channels is completed, the method 900 proceeds to step 912. In step 912, the reader determines w hether any of the RF channels is better quality than the network-assigned RF channel. In response to determining at step 912 that none of the RF channels is better quality than the network-assigned RF channel, the method 900 ends. In response to determining at step 912 that one or more of the RF channels is better quality than the network-assigned RF channel, the method 900 proceeds to step 914. In step 914, the reader replaces the network-assigned RF channel w ith a highest quality RF channel. After performing step 914, the method 900 ends.

[0089] FIG. 10 shows an example of AIoT indoor deployment scenario, in accordance with some implementations. In the illustrated embodiment, 18 readers 1004 (e.g., each reader corresponds to an AIoT-enabled gNode B) are uniformly spaced with a fixed Inter-Site Distance (ISD) equal to D within is a PF x L rectangular area 1002. The rectangular area 1002 may be located within an indoor factory’. Different ones of the readers 1004 are denoted by Rothrough Rl 7in FIG. 10. Using either the network- controlled channel selection or the autonomous dy namic channel selection approach, the R2D RF channel assigned to the yth reader Rj should not be overlapping with any direct neighboring readers with distances of D or V2D. For example, the reader R7should use an RF channel that is not overlapping with direct neighbor readers Ro, Rr, R2, R6, R8, R12,Rl3, and ff14. In some embodiments, reader-to-reader interference can be further reduced, if the R2D RF channel reuse distance is greater than 2D. In such embodiments, a greater RF channel reuse distance needs a larger number of orthogonal RF channels NR2D, which in turn requires a larger total AIoT spectrum BR D s.Contention-based Channel (Multiple) Access

[0090] Unlike cellular technology, AIoT device-to-reader communication (including the contention-based channel access procedure) is expected to be triggered by the reader. Depending on the type of R2D messages sent by the reader, several devices (or massive devices) may respond at the same time, resulting in device-to-device collisions, which corrupts or garbles response messages at the receiver end of the reader. Such collisions occur during contention-based channel (or multiple) access. When a reader initiates the contention-based access procedure, it may not have any prior knowledge of the device population within its cell coverage. In other words, the main purpose of initiating the contention-based channel access procedure is to discover individual devices and acquire their identities. On the contrary, if the reader has the device identity, the R2D message contains the identity of the intended device. In such a situation, no device-to-device collision occurs because only the intended device responds to the reader’s request message. Such an access method is known as contention-free channel access.

[0091] Using the dynamic channelization method, a set of orthogonal D2R RF channels can be made available for transmission from the device to the reader. In some embodiments, device-to-device collisions can be mitigated if each device selects a different D2R RF channel CD2R n(see FIGS. 5 and 6) to transmit its response message during contention-based channel access. For the D2R RF channel selection, the reader broadcasts (or multicasts) channelization configuration parameters to all the devices w ithin its cell coverage, which forms the first step in the contention-based access procedure. Such channelization configuration parameters include the number of D2R RF channels ND2R, the starting D2R RF channel frequency fD2Rii, the RF channel ban w idth BD2R o, the carrier-wave frequency fR2DiCWfor Device 1 and Device 2a (see Table 1), the bitmap (or a list) ID2Rindicating which D2R RF channels are not available (or available) for selection, and the dexice category. The bitmap (or list) ID2Rand the device category are optional parameters may be omitted. The bitmap (or list) ID2Rcan be used to limit the available RF channels in the D2R transmission depending on the device category. For example, available RF channels may be limited for Device t since it has limited frequency shifting capability. The device category parameter can be used by the reader to trigger a response from devices of the same category. For example, the reader sets the device category parameter to Device 1 if it transmits the carrier wave on a frequency in the FDDuplink range. As outlined in Table 1, Device 1, Device 2a, and Device 2b differ in their D2R transmission capability. Both Device 1 and Device 2a needs a carrier wave (or an RF carrier frequency) provided by an external source for D2R transmission, while Device 2b can internally generate a local RF carrier. Furthermore, the frequency shifting (or translation) capability of Device 1 is rather limited compared to Device 2a. Device 1 is unable to shift a carrier wave received on a frequency in the FDD downlink range (JDL,L- fDLiH) to a carrier frequency in the FDD uplink range (fUL L- fuL ) for D2R transmission. The frequency shifting of Device 1 is restricted to within the FDD uplink frequency range if the carrier wave is transmitted in the uplink frequency range. If the carrier wave is transmitted in the FDD downlink frequency range, then the frequency shifting range is bounded to within the downlink range. In other embodiments, an index of frequency shifts or (offset values) from the carrier-wave frequency fR2D,cw can be provided as a parameter in the channelization configuration parameters. In such embodiments, Device 1 and Device 2a can randomly select a frequency shift from the index; the index can serve as a pointer to a lookup table containing frequency shifts (or values).

[0092] Upon receipt of the configuration parameters, each device randomly selects a D2R RF channel from fD2Rfito / ivD2R-i and computes the center frequency of the corresponding RF channel using Equation (2). For Device 1, the number of RF channels in which it can choose is equal to ND2R- 1 since one RF channel is used for the carrierwave transmission. In general, Device 1 can backscatter on the same RF channel as the carrier wave, but this leads to strong self-interference from the original carrier-wave signal causing demodulation failure at the reader receiver end. For Device 2a, an FDD downlink frequency is used for carrier-wave transmission. In various embodiments, each device can use a predefined rule to select a D2R RF channel from fD2Rfito / wD2R-i (or frequency shifts or values) and computes the center frequency of the corresponding RF channel using Equation (2).

[0093] FIG. 11A shows sequence diagrams of AIoT contention-based and contention-free access methods, in accordance with some implementations. The contention-based access method 1102 comprises step 1104-1110. Although shown in a particular sequence, it should be appreciated that the steps of the contention-based access method 1102 may be performed in any suitable sequence.

[0094] In step 1104, the reader initiates the contention-based access procedure by broadcasting a contention-based access initiation message to the AIoT device population within its radio coverage area. The contention-based access initiation message may include a contention-based access configuration. The contention-based access configuration may include parameters such as the initial center frequency fD2R,t, thenumber of RF channels ND2R, the frequency resources per RF channel BD2R o, the carrierwave frequency fR2D:CWfor Device 1 and Device 2a, the bitmap (or list) ID2Rindicating which D2R RF channels are not available (or available) for selection in Step 1, and the device category7(DevCat). DevCat may be Device 1, Device 2a or Device 2b.

[0095] In step 1106, the device randomly selects one RF channel among the ND2Rchannels and computes the center frequency of the selected RF channel for D2R transmission. In embodiments when the device is Device 1, Device 1 randomly selects any RF channel among the ND2Rchannels except the one used for the carrier-wave transmission.

[0096] In step 1108, the device transmits a contention -based access response to the reader on the center frequency of the selected RF channel. In some embodiments, the contention -based access response includes parameters such as a unique identifier of the device (DevID), a device capability (DevCap), and the like. In an embodiment, the device generates a temporary identifier for DevID instead of using its actual address for security reasons.

[0097] In step 1110, the reader replies with a contention -based access acknowledgment containing the same device identifier that was received in step 1108. Upon the receipt of the contention-based access acknowledgment, the device does not reply to subsequent contention-based initiation messages. In some embodiments, step 1110 may?be optional or implicitly carried by a message in step 1114.

[0098] The contention-free access method 1112 comprises steps 1114 and 1116.Although show n in a particular sequence, it should be appreciated that the steps of the contention -free access method 1112 may be performed in any7suitable sequence.

[0099] In step 1114, the reader may choose to perform different operations depending on a particular AIoT use case and send a respective message to the device. Contents of the massage depends on the particular Al oT use case. The message may7contain the identity of the device (DevID) along w ith various parameters such as the carrier-wave frequency fR2DtCWfor Device 1 and Device 2a and the assigned D2R RF channel fD2R<nthat could be different from the one selected by' the device during the contention-based access method 1102 at step 1106. In some embodiments, DevID is optional and may be omitted from the message in step 1114.

[0100] In step 1116, the intended device replies to the reader’s message with a response. An identity' of the intended device matches with the identity of the device (DevID) that was sent with the message at step 1114. The response may include the identifier of the device (DevID) and various parameters depending on the received message in step 1114. In some embodiments, DevID is optional and may be omitted from the response in step 1116.[oioi] FIG. 11B shows a flow chart of the method 1102 for AIoT contention-based access, in accordance with some implementations. Although shown in a particular sequence, it should be appreciated that the steps of the method 1102 may be performed in any suitable sequence.

[0102] The method 1102 starts with a device receiving a contention-based access configuration from a reader in step 1118. The contention-based access configuration may include parameters such as the initial center frequency fD2R,t, the number of RF channels ND2R, the frequency resources per RF channel BD2R o, the carrier-wave frequency fR2DiCWfor Device 1 and Device 2a, the bitmap (or list) ID2Rindicating which D2R RF channels are not available (or available) for selection in Step 1, and the device category (DevCat). DevCat may be Device 1, Device 2a or Device 2b.

[0103] In step 1120, the device randomly selects one RF channel among the ND2Rchannels and computes the center frequency of the selected RF channel for D2R transmission. In embodiments when the device is Device 1, Device 1 randomly selects any RF channel among the ND2Rchannels except the one used for the carrier-wave transmission.

[0104] In step 1122, the device generates a device identifier (DevID). In an embodiment, the device identifier is a temporary identifier that is different from an actual device identifier of the device.

[0105] In step 1124, the device sends a contention-based access response to the reader on the center frequency of the selected RF channel. In some embodiments, the contention-based access response includes parameters such as the device identifier (DevID), a device capability (DevCap), and the like.

[0106] In step 1126, the device receives from the reader a contention-based access acknowiedgment including the same device identifier that was generated in step 1122 and sent to the device in step 1124. Upon the receipt of the contention-based access acknowiedgment, the device does not to reply to subsequent contention-based initiation messages. In some embodiments, step 1126 may be optional or implicitly carried by the message in step 1114 (see Figure 11A). After performing step 1126, the method 1102 ends.

[0107] In the event the population of AIoT devices is huge, there is a likelihood that two or more devices select the same RF channel during the contention-based access phase, leading to device-to-device collision at the reader. Consequently, the reader is unable to correctly receive the contention-access response message concurrently transmitted on the same RF channel by multiple devices. Such device-to-device collisions can be ameliorated by increasing the total allocated spectrum for AIoT resulting in a larger number of RF channels ND2R. In some embodiments, the reader increases the total AIoT spectrum by a certain amount in the next contention-based channel access round(or cycle) when device-to-device collisions are detected in the current cycle. At the start of the next contention-based channel access cycle, the reader transmits a contentionbased access initiation message with an updated number of RF channels ND2Ras a parameter. Hence, devices have a large pool of D2R RF channels to choose during the contention-based access method 1102 (see FIGS. 11A and 11B). Conversely, if there are unused (unoccupied or idle) RF channels detected at the end of the contention-based channel access, the reader may choose to remove some of the unused (or idle) RF channels resulting in smaller AIoT spectrum. Accordingly, the removed RF channels cannot be assigned to a device by the reader. Fig. 12 depicts the flowchart for adjusting the amount of Ambient loT spectrum reflecting device and connection density.

[0108] FIG. 12 shows a flow chart of a method 1200 for adaptive AIoT spectrum configuration for device-to-reader transmission, in accordance with some implementations. Although shown in a particular sequence, it should be appreciated that the steps of the method 1200 may be performed in any suitable sequence.

[0109] The method 1200 starts with a reader determining whether device-to-device collision is detected while performing a contention-based access cycle in step 1202. In response to detecting the device-to-device collision at step 1202, the method 1200 proceeds to step 1204. In step 1204, the reader increases the total ambient loT spectrum BD2R s(see FIG. 5 and 6). In step 1206, the reader recomputes the number of RF channels ND2R. In some embodiments, the reader may use Equation (1) to recompute the number of RF channels ND2R. In step 1208, the reader initiates a new contention-based access cycle with the updated number of RF channels ND2R. After performing step 1208, the method 1200 proceeds back to step 1202. In some embodiments, steps 1202-1208 may be repeated one or more times until no device-to-device collision is detected.

[0110] In response to detecting no device-to-device collision at step 1202, the method 1200 proceeds to step 1210. In step 1210, the reader determines whether there are unused RF channels. In response to determining at step 1210 that there are no unused RF channels, the method 1200 ends. In response to determining at step 1210 that there are unused RF channels, the method 1200 proceeds to step 1212. In step 1212, the reader removed one or more unused RF channels.

[0111] The aforementioned device-to-device collisions can be further reduced if an anti-contention protocol is applied once the device has selected an RF channel prior to sending the contention-access response during the contention access phase in step 1106 of FIG. 11A. The anti-contention protocol may comprise tree-based algorithms, Alohabased algorithms, combinations thereof, or the like.

[0112] In the following, a variant of the Aloha-based scheme, so-called p-pcrsistentAloha protocol, is described. However, it is important to note that the dynamicchannelization method (along w ith the adaptive loT spectrum method) can be applied to any anti-contention protocols and is not limited to the Aloha-based schemes including the p-persistent Aloha protocol.

[0113] The rationale for using the p-persistent anti-contention protocol is that propagation delay time of radio waves between the reader and the device is much shorter than the D2R message (or burst) transmission duration. For example, the propagation delay time of RF signals is 0.17 microseconds for a radio cell radius of 50 meters while the message transmission duration can be an order of magnitude larger than the propagation delay time.

[0114] FIG. 13A shows sequence diagrams of a contention-based channel access method with the p-persistent Aloha protocol and a contention-free access method, in accordance with some implementations. The contention-based access method 1302 with the p-persistent Aloha protocol comprises steps 1304-1310 and 1328. Although shown in a particular sequence, it should be appreciated that the steps of the contention-based access method 1302 with the p-persistent Aloha protocol may be performed in any suitable sequence.

[0115] Step 1304 is similar to step 1104 (see FIG. 11A), with an additional configuration parameter p2 being included in the contention-access initiation message in step 1304 compared to step 1104. In some embodiments, p2 is configured by the reader. Parameter p2 may be a real number ranging from 0 to 1. Parameter p2 can represent the inverse number of consecutive times in which the reader is expected to perform the contention-based access procedure. If MD2Ris the number of consecutive times the contention-based access procedure is performed, then parameter p2 = Step1306 is similar to step 1304 (see FIG. 11A) and the description is not repeated herein.

[0116] In step 1328, the device performs the p-persistent Aloha protocol. The p- persistent algorithm defines a variable, called pl. The variable pl is randomly selected from an interval [o ... 1], and the p-persistent algorithm is executed by the device. If pl is equal to or less than p2, then the device transmits the contention-access response in step 1308. Otherwise, the device waits for the next phase of contention-based channel access and repeats steps 1304-1308. In each successive contention-access initiation, the reader can reconfigure p2 as well as the dynamic channelization parameters. For example, the reader decrements the MD2Rby one in each successive contention-access initiation, that is,MD2R =MD2R ~ 1- and sets p2 =inStep13°4- Steps 1308 and 1310 are similar to steps 1108 and 1110 (see FIG. 11A), respectively, and the description is not repeated herein.

[0117] The contention-free access method 1312 comprises steps 1314 and 1316. Although shown in a particular sequence, it should be appreciated that the steps of the contention-free access method 1312 may be performed in any suitable sequence. Steps 1314 and 1316 are similar to steps 1114 and 1116 (see FIG. 11A), respectively, and the description is not repeated herein.

[0118] FIG. 13B shows a flow chart of a method 1302 for contention-based channel access method with the p-persistent Aloha protocol, in accordance with some implementations. Although shown in a particular sequence, it should be appreciated that the steps of the method 1302 may be performed in any suitable sequence. Step 1318 is similar to step 1118 (see FIG. 11B), with an additional configuration parameter p2 being included in the contention-access configuration in step 1318 compared to step 1118. Step 1320 is similar to step 1120 (see FIG. 11B) and the description is not repeated herein. In step 1130, the device performs p-persistent Aloha protocol. In one embodiment, the p- persistent Aloha protocol may be performed according to a p-persistent algorithm 1400 described below with reference to FIG. 14. In one embodiment, the p-persistent Aloha protocol may be performed according to a p-persistent algorithm 1500 described below with reference to FIG. 15. Depending of the outcome of step 1330, the method 1302 proceeds either to step 1318 or step 1322. Steps 1322, 1324, and 1326 are similar to steps 1122, 1124, and 1126 (see FIG. 11B), respectively, and the description is not repeated herein.

[0119] FIG. 14 shows a flow7chart of a p-persistent algorithm 1400, in accordance with some implementations. Although show n in a particular sequence, it should be appreciated that the steps of the p-persistent algorithm 1400 may be performed in any suitable sequence. In step 1402, a variable pl is randomly selected from an interval [o ... 1]. In step 1404, the p-persistent algorithm 1400 determines whether pl is equal to or less than p2. In response to determining at step 1404 that pl is equal to or less than p2, the p-persistent algorithm 1400 proceeds to step 1322 of FIG. 13B. In response to determining at step 1404 that pl is greater than p2, the p-persistent algorithm 1400 proceeds to step 1406. In step 1406, p2 is reconfigured. In some embodiments, the reader reconfigures p2 by decrementing the MD2Rby one, that is, MD2R= MD2R- 1, and setting p2 =1 / MD2Z?- After step 1406, the p-persistent algorithm 1400 proceeds to step 1318 of FIG. 13B.

[0120] FIG. 15 shows a flow chart of a p-persistent algorithm 1500, in accordance with some implementations. Although shown in a particular sequence, it should be appreciated that the steps of the p-persistent algorithm 1500 may be performed in any suitable sequence. In step 1502, a device determines p2. In some embodiments, thereader transmits MD2Rduring the contention-access initiation and the device setts p2 = ^ / MD2R'l n steP15°4>a variable pl is randomly selected from an interval [o ... 1]. In step 1506, the p-persistent algorithm 1500 determines whether pl is equal to or less than p2. In response to determining at step 1506 that pl is equal to or less than p2, the p- persistent algorithm 1500 proceeds to step 1322 of FIG. 13B. In response to determining at step 1506 that pl is greater than p2, the p-persistent algorithm 1500 proceeds to step 1508. In step 1508, p2 is reconfigured. In some embodiments, the reader by decrementing the MD2Rby one, that is, MD2R= MD2R- 1, and setting pAfter step 1508, the p-persistent algorithm 1500 proceeds to step 1318 of

[0121] FIG. 16 shows an example of contention-based channel access on NR timefrequency resource grid, in accordance with some implementations. In the illustrated embodiment, the carrier wave 1608 is transmitted on an FDD dow nlink frequency fR2D>n. In some embodiments, the D2R transmission of Device 2a can also take place on a selected RF channel in the FDD downlink frequency in addition to the FDD uplink frequency. Device 1 can backscatter on a selected RF channel in the FDD downlink frequency. FIG. 16 also shows a contention-access initiation message 1602, a contentionaccess acknowledgment message 1604, and a contention-access response message 1606, which are preceded by respective preamble signals. In some embodiments, the contention-access initiation message 1602, the contention-access acknowledgment message 1604, and the contention-access response message 1606 are aligned with NR OFDM symbol for ease of co-existence. In other embodiments, some or all of the contention-access initiation message 1602, the contention-access acknowledgment message 1604, and the contention-access response message 1606 are not aligned with NR OFDM symbol.

[0122] FIG. 17 shows an example of contention-based channel access on NR timefrequency resource grid for Device 1, in accordance with some implementations. FIG. 17 is similar to FIG. 16 except the carrier wave 1608 is transmitted on the first D2R frequency channel, fD2R,o-

[0123] In other embodiments, the aforementioned time-frequency contention-based channel access method (or dynamic channelization and p-persistent Aloha combination) can be simplified if the selected RF channel during the first contention-based channel access phase is reused in subsequent phases, that is, step 1306 (in FIG. 13A) is skipped but steps 1328, 1308, and 1310 are carried out. In other words, the device retains the selected RF channel in step 1306 during the first phase of the contention -based channel access. As such, this can be indicated by the absence of these parameters ND2R, BD2R oand fD2R,i in the contention-access initiation message in the subsequent phase. On the otherhand, if the aforementioned parameters are present, then the device would perform step 1306. Alternatively, the simplified time-frequency contention-based channel access method can be indicated (or triggered) by introducing a flag as a parameter in the contention-access initiation message in the subsequent phase. If the flag is enabled, then device retains the selected RF channel in step 1306 during the first phase of the contention-based channel access, which is in turn reused in the subsequent phases of the contention-based channel access.

[0124] As mentioned, the time-frequency contention-based channel access method can work with any anti-contention protocols. For example, the p-persistent Aloha scheme can be replaced by the slotted Aloha with the Q-algorilhm of the UHF RFID technology in step 1328 of FIG. 13A. The Q parameter sets the number of slots to 2Q. The p2 parameter in the contention-access initiation message can be used to send the Q parameter. Each device receiving the contention-access initiation message generates a slot count between 0 to 2Q- 1. The devices with slot count 0 transmit a contentionaccess response in step 1308 in FIG. 13A. In each subsequent phase of the contentionbased channel access, upon receiving the contention-access initiation messages, the devices decrement their slot count by one, and transmit the contention-access response if slot count equal to 0.Static Channelization

[0125] Unlike dynamic channelization, the total allocated spectrum for Ambient loTBD2R sand the frequency resources per physical channel BD2R oare fixed or preconfigured. Hence, the center frequency fnof the RF channel CD2R nis also fixed. The dynamic channelization parameters which need to be transmitted to the device include the initial center frequency f and p2 in step 1304 (see FIG 13A) or in step 1104 (see FIG 11A) of the contention-based access procedure. The contention-based access procedure with and without p-persistent protocol remains the same.

[0126] The following references are incorporated herein by reference as if reproduced in their entireties.[1] 3GPP RP-240826, New SID: Study on solutions for Ambient loT (Internet of Things) in NR, Huawei, March 2024; and[2] 3GPP TR 38.848, Study on Ambient loT (Internet of Things) in RAN, Release 18, 2023.

[0127] Figure 18 illustrates an example communications system 1800. Communications system 1800 includes an access node 1810 serving user equipments (UEs) within coverage area 1801, such as UEs 1820. In a first operating mode, communications to and from a UE passes through access node 1810 with a coverage areai8oi. The access node 1810 is connected to a backhaul network 1815 for connecting to the internet, operations and management, and so forth. In a second operating mode, communications to and from a UE do not pass through access node 1810, however, access node 1810 typically allocates resources used by the UE to communicate when specific conditions are met. Communications between a pair of UEs 1820 can use a sidelink connection (shown as two separate one-way connections 1825). In Figure 18, the sideline communication is occurring between two UEs operating inside of coverage area 1801. However, sidelink communications, in general, can occur when UEs 1820 are both outside coverage area 1801, both inside coverage area 1801, or one inside and the other outside coverage area 1801. Communication between a UE and access node pair occur over uni-directional communication links, where the communication links between the UE and the access node are referred to as uplinks 1830, and the communication links between the access node and UE is referred to as downlinks 1835.

[0128] Access nodes may also be commonly referred to as Node Bs, evolved Node Bs (eNBs), next generation (NG) Node Bs (gNBs), master eNBs (MeNBs), secondary eNBs (SeNBs), master gNBs (MgNBs), secondary gNBs (SgNBs), network controllers, control nodes, base stations, access points, transmission points (TPs), transmission-reception points (TRPs), cells, carriers, macro cells, femtocells, pico cells, and so on, while UEs may also be commonly referred to as mobile stations, mobiles, terminals, users, subscribers, stations, and the like. Access nodes may provide wireless access in accordance with one or more wireless communication protocols, e.g., the Third Generation Partnership Project (3GPP) long term evolution (LTE), LTE advanced (LTE- A), 5G, 5G LTE, 5G NR, sixth generation (6G), High Speed Packet Access (HSPA), the IEEE 802.11 family of standards, such as 802.na / b / g / n / ac / ad / ax / ay / be, etc. While it is understood that communications systems may employ multiple access nodes capable of communicating with a number of UEs, only one access node and two UEs are illustrated for simplicity.

[0129] Figure 19 illustrates an example communication system 1900. In general, the system 1900 enables multiple wireless or wired users to transmit and receive data and other content. The system 1900 may implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), or non-orthogonal multiple access (NOMA).

[0130] In this example, the communication system 1900 includes electronic devices(ED) 19103-19100, radio access networks (RANs) I92oa-i92ob, a core network 1930, a public switched telephone network (PSTN) 1940, the Internet 1950, and other networksi960. While certain numbers of these components or elements are shown in Figure 19, any number of these components or elements may be included in the system 1900.

[0131] The EDs 19103-19100 are configured to operate or communicate in the system 1900. For example, the EDs 19103-19100 are configured to transmit or receive via w ireless or w ired communication channels. Each ED 19103-19100 represents any suitable end user device and may include such devices (or may be referred to) as a user equipment or device (UE), wireless transmit or receive unit (WTRU), mobile station, fixed or mobile subscriber unit, cellular telephone, personal digital assistant (PDA), smartphone, laptop, computer, touchpad, wireless sensor, or consumer electronics device.

[0132] The RANs I92oa-i92ob here include base stations lgyoa-igyob, respectively. Each base station i970a-i970b is configured to wirelessly interface with one or more of the EDs 19103-19100 to enable access to the core network 1930, the PSTN 1940, the Internet 1950, or the other networks i960. For example, the base stations I97oa-i97ob may include (or be) one or more of several well-known devices, such as a base transceiver station (BTS), a Node-B (NodeB), an evolved NodeB (eNB), a Next Generation (NG) NodeB (gNB), a gNB centralized unit (gNB-CU), a gNB distributed unit (gNB-DU), a Home NodeB, a Home eNodeB, a site controller, an access point (AP), or a wireless router. The EDs 19103-19100 are configured to interface and communicate with the Internet 1950 and may access the core network 1930, the PSTN 1940, or the other networks i960.

[0133] In the embodiment shown in Figure 19, the base station 1970a forms part of the RAN 1920a, which may include other base stations, elements, or devices. Also, the base station 1970b forms part of the RAN 1920b, which may include other base stations, elements, or devices. Each base station I97oa-i97ob operates to transmit or receive wireless signals within a particular geographic region or area, sometimes referred to as a “cell.” In some embodiments, multiple-input multiple-output (MIMO) technology may be employed having multiple transceivers for each cell.

[0134] The base stations i970a-i970b communicate with one or more of the EDs 19103-19100 over one or more air interfaces 1990 using wireless communication links. The air interfaces 1990 may utilize any suitable radio access technology.

[0135] It is contemplated that the system 1900 may use multiple channel access functionality, including such schemes as described above. In particular embodiments, the base stations and EDs implement 5G New Radio (NR), LTE, LTE-A, or LTE-B. Of course, other multiple access schemes and wireless protocols may be utilized.

[0136] The RANs I92oa-i92ob are in communication with the core network 1930 to provide the EDs 19103-19100 with voice, data, application, Voice over Internet Protocol(VoIP), or other services. Understandably, the RANs I92oa-i92ob or the core network 1930 may be in direct or indirect communication with one or more other RANs (not shown). The core network 1930 may also serve as a gateway access for other networks (such as the PSTN 1940, the Internet 1950, and the other networks i960). In addition, some or all of the EDs 19103-19100 may include functionality for communicating with different wireless networks over different wireless links using different wireless technologies or protocols. Instead of wireless communication (or in addition thereto), the EDs may communicate via wired communication channels to a service provider or switch (not show n), and to the Internet 1950.

[0137] Although Figure 19 illustrates one example of a communication system, various changes may be made to Figure 19. For example, the communication system 1900 could include any number of EDs, base stations, networks, or other components in any suitable configuration.

[0138] Figures 20A and 20B illustrate example devices that may implement the methods and teachings according to this disclosure. In particular, Figure 20A illustrates an example ED 2010, and Figure 20B illustrates an example base station 2070. These components could be used in the system 1900 or in any other suitable system.

[0139] As shown in Figure 20A, the ED 2010 includes at least one processing unit 2000. The processing unit 2000 implements various processing operations of the ED 2010. For example, the processing unit 2000 could perform signal coding, data processing, power control, input / output processing, or any other functionality enabling the ED 2010 to operate in the system 1900. The processing unit 2000 also supports the methods and teachings described in more detail above. Each processing unit 2000 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 2000 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

[0140] The ED 2010 also includes at least one transceiver 2002. The transceiver 2002 is configured to modulate data or other content for transmission by at least one antenna or NIC (Network Interface Controller) 2004. The transceiver 2002 is also configured to demodulate data or other content received by the at least one antenna 2004. Each transceiver 2002 includes any suitable structure for generating signals for wireless or wired transmission or processing signals received wirelessly or by wire. Each antenna 2004 includes any suitable structure for transmitting or receiving wireless or wired signals. One or multiple transceivers 2002 could be used in the ED 2010, and one or multiple antennas 2004 could be used in the ED 2010. Although shown as a singlefunctional unit, a transceiver 2002 could also be implemented using at least one transmitter and at least one separate receiver.

[0141] The ED 2010 further includes one or more input / output devices 2006 or interfaces (such as a wired interface to the Internet 1950). The input / output devices 2006 facilitate interaction with a user or other devices (network communications) in the network. Each input / output device 2006 includes any suitable structure for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen, including network interface communications.

[0142] In addition, the ED 2010 includes at least one memory 2008. The memory’ 2008 stores instructions and data used, generated, or collected by the ED 2010. For example, the memory’ 2008 could store software or firmw are instructions executed by the processing unit(s) 2000 and data used to reduce or eliminate interference in incoming signals. Each memory 2008 includes any suitable volatile or non-volatile storage and retrieval device(s). Any suitable type of memory’ may be used, such as random access memory (RAM), read only memory (ROM), hard disk, optical disc, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, and the like.

[0143] As shown in Figure 20B, the base station 2070 includes at least one processing unit 2050, at least one transceiver 2052, which includes functionality for a transmitter and a receiver, one or more antennas 2056, at least one memory 2058, and one or more input / output devices or interfaces 2066. A scheduler, which w’ould be understood by one skilled in the art, is coupled to the processing unit 2050. The scheduler could be included within or operated separately from the base station 2070. The processing unit 2050 implements various processing operations of the base station 2070, such as signal coding, data processing, power control, input / output processing, or any other functionality. The processing unit 2050 can also support the methods and teachings described in more detail above. Each processing unit 2050 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 2050 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

[0144] Each transceiver 2052 includes any suitable structure for generating signals for wireless or wired transmission to one or more EDs or other devices. Each transceiver 2052 further includes any suitable structure for processing signals received wirelessly or by wire from one or more EDs or other devices. Although shown combined as a transceiver 2052, a transmitter and a receiver could be separate components. Each antenna 2056 includes any suitable structure for transmitting or receiving wireless orwired signals. While a common antenna 2056 is shown here as being coupled to the transceiver 2052, one or more antennas 2056 could be coupled to the transceiver(s) 2052, allow ing separate antennas 2056 to be coupled to the transmitter and the receiver if equipped as separate components. Each memoiy 2058 includes any suitable volatile or non-volatile storage and retrieval device(s). Each input / output device 2066 facilitates interaction with a user or other devices (network communications) in the network. Each input / output device 2066 includes any suitable structure for providing information to or receiving / providing information from a user, including network interface communications.

[0145] Figure 21 is a block diagram of a computing system 2100 that may be used for implementing the devices and methods disclosed herein. For example, the computing system can be any entity of UE, access network (AN), mobility management (MM), session management (SM), user plane gateway (UPGW), or access stratum (AS). Specific devices may utilize all of the components shown or only a subset of the components, and levels of integration may vaiy from device to dev ice. Furthermore, a device may contain multiple instances of a component, such as multiple processing units, processors, memories, transmitters, receivers, etc. The computing system 2100 includes a processing unit 2102. The processing unit includes a central processing unit (CPU) 2114, memoiy 2108, and may further include a mass storage device 2104, a video adapter 2110, and an I / O interface 2112 connected to a bus 2120.

[0146] The bus 2120 may be one or more of any type of several bus architectures including a memory bus or memory controller, a peripheral bus, or a video bus. The CPU 2114 may comprise any type of electronic data processor. The memoiy 2108 may comprise any type of non-transitory system memory such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), or a combination thereof. In an embodiment, the memoiy 2108 may include ROM for use at boot-up, and DRAM for program and data storage for use while executing programs.

[0147] The mass storage 2104 may comprise any type of non-transitoiy storage device configured to store data, programs, and other information and to make the data, programs, and other information accessible via the bus 2120. The mass storage 2104 may comprise, for example, one or more of a solid state drive, hard disk drive, a magnetic disk drive, or an optical disk drive.

[0148] The video adapter 2110 and the I / O interface 2112 provide interfaces to couple external input and output devices to the processing unit 2102. As illustrated, examples of input and output devices include a display 2118 coupled to the video adapter 2110 and a mouse, keyboard, or printer 2116 coupled to the I / O interface 2112. Otherdevices may be coupled to the processing unit 2102, and additional or fewer interface cards may be utilized. For example, a serial interface such as Universal Serial Bus (USB) (not shown) may be used to provide an interface for an external device.

[0149] The processing unit 2102 also includes one or more network interfaces 2106, which may comprise wired links, such as an Ethernet cable, or wireless links to access nodes or different networks. The network interfaces 2106 allow the processing unit 2102 to communicate with remote units via the networks. For example, the netw ork interfaces 2106 may provide wireless communication via one or more transmitters / transmit antennas and one or more receivers / receive antennas. In an embodiment, the processing unit 2102 is coupled to a local-area network 2122 or a wide-area network for data processing and communications with remote devices, such as other processing units, the Internet, or remote storage facilities.

[0150] It should be appreciated that one or more steps of the embodiment methods provided herein may be performed by corresponding units or modules. For example, a signal may be transmitted by a transmitting unit or a transmitting module. A signal may be received by a receiving unit or a receiving module. A signal may be processed by a processing unit or a processing module. Other steps may be performed by a performing unit or module, a generating unit or module, an obtaining unit or module, a setting unit or module, an adjusting unit or module, an increasing unit or module, a decreasing unit or module, a determining unit or module, a modifying unit or module, a reducing unit or module, a removing unit or module, or a selecting unit or module. The respective units or modules may be hardware, software, or a combination thereof. For instance, one or more of the units or modules may be an integrated circuit, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0151] Although the description has been described in detail, it should be understood that various changes, substitutions and alterations can be made without departing from the spirit and scope of this disclosure as defined by the appended claims. Moreover, the scope of the disclosure is not intended to be limited to the particular embodiments described herein, as one of ordinary skill in the art will readily appreciate from this disclosure that processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, may perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein. Accordingly, the appended claims are intended to include w ithin their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

[0152] Although the description has been described in detail, it should be understood that various changes, substitutions and alterations can be made withoutdeparting from the spirit and scope of this disclosure as defined by the appended claims. Moreover, the scope of the disclosure is not intended to be limited to the particular embodiments described herein, as one of ordinary7skill in the art will readily appreciate from this disclosure that processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, may perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claims

WHAT IS CLAIMED IS:

1. A method performed by an Internet-of-Things (loT) device, the method comprising: receiving, by the loT device from a reader, a contention-based access configuration comprising information for a plurality of radio-frequency (RF) channels that can be used by the loT device for uplink communication with the reader; selecting, by the loT device based on the contention -based access configuration, a first RF channel from the plurality of RF channels; sending, by the loT device to the reader using the first RF channel, a contentionaccess response, the contention-access response indicating a device identifier of the loT device; and receiving, by the loT device from the reader, a contention-access acknowledgment indicating the device identifier.

2. The method of claim t, wherein the contention-based access configuration indicates an initial center frequency, a number of RF channels, and frequency resources in each of the plurality of RF channels.

3. The method of claim 2, wherein the contention-based access configuration further indicates a carrier-wave frequency, and the carrier-wave frequency is within an uplink band used by the loT device for the uplink communication w ith the reader.

4. The method of claim 2, wherein the contention-based access configuration further indicates a carrier-wave frequency, and the carrier-wave frequency is within a downlink band used by the loT device for downlink communication with the reader.

5. The method of any of claims 2 to 4, wherein the contention-based access configuration further indicates availability of the plurality of RF channels and a device category7.

6. The method of claim 5, wherein the contention-based access configuration comprises a bitmap indicating the availability of the plurality of RF channels.

7. The method of claim 5, wherein the contention-based access configuration comprises a list indicating the availability of the plurality of RF channels.

8. The method of any of claims 1 to 7, wherein the reader comprises a 5th generation (5G) cellular base station, an intermediate node, an assisting node, or a user equipment (UE).

9. The method of any of claims 2 to 8, wherein the contention-based access configuration further indicates a collision avoidance parameter.

10. The method of claim 9, further comprising: after the selecting the first RF channel, selecting, by the loT device, a random number between o and 1, the sending the contention-access response comprising: sending the contention-access response in response to determining, by the loT device, that the random number is less than or equal to the collision avoidance parameter.

11. The method of any of claims 1 to 10, further comprising: receiving, by the loT device from the reader, a message indicating the device identifier and a center frequency of a second RF channel; and sending, by the loT device to the reader using the second RF channel, a response to the message.

12. The method of claim 11, wherein the first RF channel is same as the second RF channel, or the first RF channel is different from the second RF channel.

13. The method of any of claims 1 to 12, wherein the plurality of RF channels are within a new radio (NR) guard band or an NR inner band.

14. A method performed by a reader, the method comprising: scanning, by the reader, a plurality of radio-frequency (RF) channels; determining, by the reader, qualities of the plurality of RF channels; and determining, by the reader, whether to keep or replace an assigned RF channel based on determining if at least one RF channel of the plurality of RF channels has a better quality than the assigned RF channel.

15. The method of claim 14, further comprising: in response to determining, by the reader, that at least one of the plurality of RF channels has the better quality than the assigned RF channel, replacing, by the reader,the assigned RF channel w ith a highest quality RF channel from the plurality of RF channels.

16. The method of claim 14, further comprising: in response to determining, by the reader, that none of the plurality of RF channels has the better quality than the assigned RF channel, keeping, by the reader, the assigned RF channel.

17. The method of any of claims 14 to 16, wherein the plurality of RF channels are within a new radio (NR) guard band or an NR inner band.

18. The method of any of claims 14 to 17, wherein the plurality of RF channels are used for downlink communication w ith Internet-of-Things (loT) devices.

19. A method performed by a reader, the method comprising: communicating with Internet-of-Things (loT) devices using a plurality of assigned radio-frequency (RF) channels for uplink communication with the loT devices; and determining, by the reader, whether at least one device-to-device collision is detected in the plurality of assigned RF.

20. The method of claim 19, further comprising: in response to determining, by the reader, that the at least one device-to-device collision is detected: increasing, by the reader, a total allocated spectrum for the uplink communication with the loT devices; generating, by the reader, a plurality of updated RF channels for the uplink communication with the loT devices based on the total allocated spectrum; determining, by the reader, a number of the updated RF channels; assigning, by the reader, the plurality of updated RF channels; and transmitting, by the reader to the loT devices, a contention-based access configuration indicating the number of the updated RF channels.

21. The method of claim 19, further comprising: in response to determining, by the reader, that no device-to-device collisions are detected: determining, by the reader, whether at least one of the plurality of assigned RF channels is unused; andremoving, by the reader, unused RF channels from the plurality of assigned RF channels.

22. The method of any of claims 19 to 21, wherein the plurality of assigned RF channels are within a new radio (NR) guard band or an NR inner band.

23. An Internet-of-Things (loT) device, comprising: at least one processor; and a non-transitory computer readable storage medium storing programming, the programming including instructions that, when executed by the at least one processor, cause the loT device to perform a method according to any of claims 1-13.

24. A reader, comprising: at least one processor; and a non-transitory computer readable storage medium storing programming, the programming including instructions that, when executed by the at least one processor, cause the reader to perform a method according to any of claims 14-18.

25. A reader, comprising: at least one processor; and a non-transitory computer readable storage medium storing programming, the programming including instructions that, when executed by the at least one processor, cause the reader to perform a method according to any of claims 19-22.

26. A non-transitory computer-readable medium having instructions stored thereon that, when executed by an Internet-of-Things (loT) device, cause the loT device to perform a method according to any of claims 1-13.

27. A non-transitory computer-readable medium having instructions stored thereon that, when executed by a reader, cause the reader to perform a method according to any of claims 14-18.

28. A non-transitory computer-readable medium having instructions stored thereon that, when executed by a reader, cause the reader to perform a method according to any of claims 19-22.

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