Methods for ambient internet of things (IOT) device in-band selectivity

Abstract

In accordance with implementations, a WTRU receives a carrier wave (CW). The WTRU receives an Ambient Internet of Things (AIoT) Reader to Device (R2D) signal associated with the CW. At least a portion of the AIoT R2D signal and the CW are received simultaneously.

Description

Methods for Ambient Internet of Things (loT) Device In-band SelectivityCROSS-REFERENCE TO RELATED APPLICATION

[0001] This patent application claims priority to U.S. Provisional Application No. 63 / 658,291, filed on June 10, 2024, and entitled “Methods for Ambient Internet of Things (loT) Device In-band Selectivity,” application of which is hereby incorporated by reference herein as if reproduced in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates generally to wireless communications, and, in particular embodiments, to systems and methods for Ambient loT device in-band selectivity.BACKGROUND

[0003] Within the framework of Release 19, the Third Generation Partnership Project (3GPP) studies a new device, Ambient Internet of Things (loT) device, aiming at expanding the 5th generation (5G) New Radio (NR) device ecosystem. In comparison to 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 factors and capabilities to harvest energy sources from the environment such as electromagnetic waves, solar or light, kinetic or vibration, wind, thermal, among others. Additionally, these Ambient loT devices may be equipped with limited energy storage (e.g., supercapacitors) for storing electric energy harvested from ambient energy sources. As a result, the high maintenance costs and safety hazards due to the manual changing or recharging of batteries on loT devices can be eliminated, leading to an eco-friendly and sustainable technology of the future, and reducing the carbon footprint of today’s supply chain.SUMMARY

[0004] Technical advantages are generally achieved, by implementations of this disclosure which describe methods, apparatus, and system.

[0005] In accordance w ith implementations, a WTRU receives a carrier wave (CW). The WTRU receives an Ambient Internet of Things (AIoT) Reader to Device (R2D) signal associated with the CW. At least a portion of the AIoT R2D signal and the CW are received simultaneously. i[ooo6] In some implementations, the WTRU may receive control information. The WTRU may receive a payload of a data packet in the AIoT R2D signal following the control information. The WTRU may demodulate the payload of the data packet based on the control information and the CW.

[0007] In some implementations, the control information may be in a packet header of the data packet before the payload of the data packet.

[0008] In some implementations, the control information may be in the payload of the data packet following a preamble of the data packet.

[0009] In some implementations, the control information may be in a second data packet different from the data packet.

[0010] In some implementations, the control information may indicate that the data packet is configured to be received using the CW.

[0011] In some implementations, the control information may indicate a frequency offset between the CW and the AIoT R2D signal.

[0012] In some implementations, the frequency offset may be greater than a bandwidth of the AIoT R2D signal and less than 3 times the bandwidth of the AIoT R2D signal.

[0013] In some implementations, the frequency offset may be at least 3 times a bandwidth of the AIoT R2D signal.

[0014] In some implementations, the frequency offset may be between the CW and a center frequency of the AIoT R2D signal.

[0015] In some implementations, the control information may further indicate a data rate of the data packet and a bandwidth of the AIoT R2D signal.

[0016] In some implementations, the control information may be received in a first envelope of a first signal with a first frequency offset of 0 in a baseband (BB) mode. The payload of the data packet may be received in a second envelope of a second signal with a second frequency offset not equal to o in an intermediate frequency (IF) mode.

[0017] In some implementations, the control information may be time division multiplexed (TDMed) with a first signal intended for another terminal device. The payload of the data packet may be frequency division multiplexed (FDMed) with a second signal. The second signal may be the same as or different from the first signal.

[0018] In some implementations, the CW may include a single tone signal.

[0019] In some implementations, the WTRU may receive a second signal requesting a device capability. The WTRU may transmit an indication of a capability of a receiver of the WTRU supporting in-band selectivity.

[0020] In some implementations, a payload of a data packet in the AIoT R2D signal may be received simultaneously with the CW.

[0021] In accordance with implementations, a network system transmits a carrier wave (CW). The network system transmits an Ambient Internet of Things (AIoT) Reader to Device (R2D) signal associated with the CW. At least a portion of the AIoT R2D signal and the CW are transmitted simultaneously.

[0022] In some implementations, at least a portion of the AIoT R2D signal and theCW may be transmitted simultaneously.

[0023] In some implementations, the AIoT R2D signal may be transmitted by a reader device of the network system. The CW may be transmitted by a CW node of the network system different from the reader device.

[0024] In some implementations, the CW and the AIoT R2D signal associated with the CW may be transmitted to a wireless transmit / receive unit (WTRU).

[0025] In some implementations, the network system may transmit control information to a WTRU. The network system may transmit a payload of a data packet in the AIoT R2D signal following the control information. The control information may be used by the WTRU to demodulate the payload of the data packet.

[0026] In some implementations, the control information may be in a packet header of the data packet before the payload of the data packet.

[0027] In some implementations, the control information may be in the payload of the data packet following a preamble of the data packet.

[0028] In some implementations, the control information may be in a second data packet different from the data packet.

[0029] In some implementations, the control information may indicate that the data packet is configured to be received using the CW.

[0030] In some implementations, the control information may indicate a frequency offset between the CW and the AIoT R2D signal.

[0031] In some implementations, the frequency offset may be greater than a bandwidth of the AIoT R2D signal and less than 3 times the bandwidth of the AIoT R2D signal.

[0032] In some implementations, the frequency offset may be at least 3 times a bandwidth of the AIoT R2D signal.

[0033] In some implementations, the frequency offset may be between the CW and a center frequency of the AIoT R2D signal.

[0034] In some implementations, the control information may further indicate a data rate of the data packet and a bandwidth of the AIoT R2D signal.

[0035] In some implementations, the control information may be time division multiplexed (TDMed) w ith a first signal intended for another terminal device. The payload of the data packet may be frequency division multiplexed (FDMed) w ith a second signal. The second signal may be the same as or different from the first signal.

[0036] In some implementations, the CW may include a single tone signal.

[0037] In some implementations, the network system may transmit to a WTRU a second signal requesting a device capability. The network may receive an indication of a capability of a receiver of the WTRU supporting in-band selectivity.

[0038] In some implementations, a payload of a data packet in the AIoT R2D signal may be transmitted simultaneously with the CW.

[0039] The techniques for AIoT device in-band selectivity described in this disclosure provide technical advantages over conventional approaches. By leveraging externally provided CW signals during Reader to Device (R2D) transmissions, the described techniques could enable in-band channel selectivity for low -power AIoT devices without requiring complex and power-consume local oscillators. The described techniques could allow’ FDM of multiple AIoT R2D transmissions and / or alongside other 5G NR transmissions, improving system spectral efficiency. The described techniques could also accommodate both legacy AIoT devices with RFED receivers and enhanced devices with RFED+ capabilities through back' ward-compatible protocols, while enabling simultaneous operation of multiple AIoT channels.BRIEF DESCRIPTION OF THE DRAWINGS

[0040] For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

[0041] FIGs. 1A-1E illustrate topologies of Ambient loT connectivity, in accordance with some implementations;

[0042] FIG. 1F shows the architecture for Device 1 with the RF envelope detection receiver, in accordance w ith some implementations;

[0043] FIG. 1G shows the architecture for Device 2a with the IF envelope detection receiver, in accordance with some implementations;

[0044] FIG. 1H shows the architecture for Device 2b with the ZIF envelope detection receiver, in accordance with some implementations;

[0045] FIG. 11 illustrates Topology 1 with CW node outside of the topology, in accordance with some implementations;

[0046] FIG. 2 illustrates technical issues of supporting FDM without in-band channel selectivity, in accordance with some implementations;

[0047] FIG. 3A shows an example of a reader transmitting both the R2D signal and the CW signal simultaneously, in accordance with some implementations;

[0048] FIG. 3B shows an example of a separate CW node transmitting the CW signal while the reader is transmitting the R2D signal, in accordance w ith some implementations;

[0049] FIG. 3C shows an example of a single reader transmitting multiple R2D signals using FDM and a CW signal, in accordance with some implementations;

[0050] FIG. 3D shows an example of a single reader transmitting multiple R2D signals using FDM and multiple CW nodes, each transmitting a CW signal at the same time, in accordance with some implementations;

[0051] FIG. 3E shows an example of multiple readers transmitting multiple R2D signals and multiple CW signals using different frequency resources, in accordance with some implementations;

[0052] FIG. 4 shows an example PRDCH data packet structure including a packet header, in accordance with some implementations;

[0053] FIG. 5 shows an example flow diagram describing the procedure for an AIoT reader to address a mixture of AIoT devices, in accordance with some implementations;

[0054] FIG. 6 illustrates an example flow diagram describing the procedure of receiving for an AIoT device with the RFED receiver, in accordance with some implementations;

[0055] FIGs. 7A-7C shows examples of flow diagrams describing the procedures of receiving for an AIoT device with the RFED+ receiver, in accordance with some implementations;

[0056] FIG. 8 illustrates an example PRDCH data packet structure and control information fields within the payload, in accordance w ith some implementations;

[0057] FIG. 9A shows a simplified block diagram of an RFED receiver, in accordance with some implementations;

[0058] FIG. 9B illustrates an example of the RF and baseband spectrum without any interference, in accordance with some implementations;

[0059] FIG. 9C illustrates an example of the RF and baseband spectrum with a single tone CW present, in accordance with some implementations;

[0060] FIG. 10A shows a simplified block diagram of an example implementation of RFED+ receiver, in accordance with some implementations;

[0061] FIG. 10B illustrates an example of the RF and baseband spectrum with a single tone CW and other FDM transmission present, in accordance with some implementations;

[0062] FIG. 11 illustrates an example of the RF spectrum of the reader transmitting both the packet header and a CW signal, in accordance with some implementations;

[0063] FIG. 12A illustrates an example of R2D transmission in a deployment w ith a single reader and two CW nodes, in accordance with some implementations;

[0064] FIG. 12B illustrates an example of D2R transmission in a deployment with a single reader and two CW nodes, in accordance with some implementations;

[0065] FIG. 13 illustrates an example of RF resource allocation for multi-channel AIoT operations, in accordance with some implementations;

[0066] FIGs. 14A and 14B illustrate an example of a single reader (e.g., BTS) operating 2 parallel R2D channels, in accordance with some implementations;

[0067] FIGs. 15A and 15B illustrate an example of reader operating two parallel R2D channels simultaneously, in accordance with some implementations;

[0068] FIG. 16A shows a flow' chart of a method performed by a wireless device, in accordance with some implementations;

[0069] FIG. 16B shows a flow' chart of a method performed by a system on the network side, in accordance with some implementations;

[0070] FIG. 17 illustrates an example wireless communication system, in accordance with some implementations;

[0071] FIG. 18 illustrates an example communication system, in accordance with some implementations;

[0072] FIGs. 19A and 19B illustrate example devices, in accordance w ith some implementations; and

[0073] FIG. 20 shows a block diagram of a computing system, in accordance with some implementations.

[0074] 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

[0075] Ambient loT technology enables massive deployment of battery-free and low- cost loT devices, which opens newruse cases and provides added value across the supply chain. To date, 3GPP groups Ambient loT use cases into four broad categories: (1) inventory7, (2) sensor, (3) positioning, and (4) command. The inventory7and command use cases are selected for study in Release 19.

[0076] In the 3GPP Release t9 study scope, an Ambient loT device can connect either directly to a gNode B or indirectly via an intermediate node (e.g., UE). The former network connectivity structure is referred to as Topology 1 (e.g., gNode B (gNB) <=> Ambient loT device), and the latter is referred to as Topology 2 (e.g., gNB < => Intermediate Node <=> Ambient loT device). There are two additional network connectivity topologies, namely Topology 3 (gNB <=> assisting node <=> ambient loT Device < = > gNB), and Topology 4 (UE <=> Ambient loT device). The four topologies are illustrated in FIGs. 1A-1E. FIG. 1A illustrates Topology 1. FIG. 1B illustrates Topology2. FIG. 1C illustrates Topology 3 with the downlink assist. FIG. 1D illustrates Topology 3 with the uplink assist. FIG. 1E illustrates Topology 4. Even though Topologies 3 and 4 are considered out of scope in the current 3GPP release, the implementations described herein are applicable to all the aforementioned topologies.

[0077] In 3GPP discussions, the link from a gNB or an intermediate node UE to an Ambient loT (AIoT) device is defined as a reader to device (R2D) link, and the link from an AloT device to a gNB or an intermediate node UE is defined as a device to reader (D2R) link. In a frequency division duplex (FDD) spectrum allocation, the R2D link can be transmitted over the uplink or downlink spectrum; likewise, the D2R link can be transmitted over the uplink or downlink spectrum. The implementations described herein relate to, but are not limited to, the transmission and reception in the R2D link.

[0078] In addition, the following types of Ambient loT devices are defined.

[0079] Device 1: Device 1 consumes approximately 1 LIW peak power. Device 1 has energy storage. The initial sampling frequency offset (SFO) is up to 1OXppm. Neither DL nor UL amplification is in the device. The device’s UL transmission is backscattered on a carrier wave provided externally.

[0080] Device 2a: Device 2a consumes a few hundred nW or fewer peak power. Device 2a has energy storage. The initial sampling frequency offset (SFO) is up to 1OXppm. Both DL and / or UL amplification is in the device. The device’s UL transmission is backscattered on a carrier wave provided externally.

[0081] Device 2b: Device 2b consumes < a few hundred pW or fewer peak power. Device 2b has energy storage. The initial sampling frequency offset (SFO) is up to ioxppm. Both DL and / or UL amplification is in the device. The device’s UL transmission is generated internally by the device.

[0082] Reference device architectures have been discussed in 3GPP meetings. For the AIoT device receiver, the candidate architectures under discussion are: (1) radio frequency (RF) envelope detection (ED); (2) intermediate frequency (IF) envelope detection; and (3) zero IF (ZIF) detection. FIGs. 1F-1H show some device architectures with the 3 types of receivers. In FIG. 1F, the receiver uses RF envelope detection to receive the signal from the antenna after a matching network and RF bandpass filter (BPF). In FIG. 1G, the receiver first down-converts the signal from the antenna after a matching network, RF BPF and low noise amplifier (LNA) to an IF using a mixer and a local oscillator (LO). The IF signal is then filtered and detected with an envelope detector. In FIG. 1H, the signal from antenna after matching network, RF BPF, and LNA is converted directly to the baseband using a mixer and a LO. The baseband signal is then filtered by a lowpass filter (LPF) and detected with a comparator. In FIGs. 1F-1H, PMU may stand for power management unit, BB baseband, PLL phase lock loop, ADC analog digital convertor, and PA power amplifier.

[0083] The matching network and the RF bandpass filter are usually wideband to cover the entire operating band for the device. Due to cost and complexity considerations, the RF bandpass filter bandwidth is usually much w ider than the bandwidth of the AIoT R2D transmission signal. With RF envelope detection, all the RF signals within the bandwidth of the RF bandpass filter (BPF) are converted to the baseband. There is no in-band channel selectivity. With IF envelope detection and ZIF detection, in-band channel selectivity is possible by using narrower bandwidth filters at IF or baseband frequencies. The LO determines the frequency of the selected channel, and the IF or the baseband filter determines the bandwidth of the selected channel.

[0084] For the D2R link, Device 1 and Device 2a rely on backscattering a carrier wave (CW) provided externally by a CW node (e.g., emitter) to transmit. The CW node can be the same as the base station within the topology, or a separate node outside of the topology. FIG. 11 illustrates Topology 1 with a CW node outside of the topology. The AIoT device 162 backscatters the CW signal by switching between impedance loads to the antenna to change its reflection coefficient, which produces a modulated signal on the CW that can be detected by the reader. The advantage of backscattering is that the AIoT device 162 does not require an accurate internal LO, which can increase both complexity and power consumption.

[0085] The CW waveform can be at least a single unmodulated continuous wave tone. Other types of CW waveforms can also be considered and utilized.

[0086] Due to the lack of in-band channel selectivity for devices with RF envelope detection, the R2D link for such devices operates in a time division multiplexing (TDM) mode with other 5G NR transmissions. Simultaneous 5G NR transmissions even at different frequencies, as long as they are within the RF filter bandwidth of the device, will cause interference to the received R2D transmission. The data rate on the R2D link is typically lower than the data rate of 5G NR transmissions. Operating the system in the TDM mode results in much lower overall system spectral efficiency. In addition, simultaneous operation of multiple R2D links on different frequency channels causes the same interference problem at the device. This interference severely limits the ability for the system to increase the AIoT service throughput by taking advantage of the available frequency resources. This situation is illustrated in FIG. 2. As shown in FIG. 2, without in-band channel selectivity, frequency duplex multiplexing (FDM) of the AIoT R2D link signal with other signals cannot be supported.

[0087] The implementations described in this disclosure provides technical solutions to enable in-band channel selectivity for AIoT devices that lack such capabilities on their own, which in turn enables the coexistence of the AIoT service with other 5G NR services through frequency division multiplexing (FDM), and the simultaneous operations of multiple AIoT channels.

[0088] Channel selectivity is usually implemented using radio architectures with heterodyne or homodyne receivers, where the signal is first converted to IF or baseband frequency and then filtered with an IF or baseband filter. This requires an accurate LO to select the channel at the appropriate frequency. However, the power and cost constraints of some of the large volume AIoT devices do not allow’ such methods for channel

[0089] The implementations of this disclosure provide the single tone carrier wave(CW) signals externally to the AIoT devices during R2D transmissions to enable channel selectivity at the AIoT devices. Similar to the D2R link using backscattering where an externally provided carrier wave is leveraged by the AIoT devices to avoid generating LO internally, for the R2D link, the AIoT devices can also use the externally provided carrier wave as an LO to achieve channel selectivity w ith low power consumption. This solution enables the reader to frequency division multiplex multiple parallel AIoT R2D transmissions and other 5G NR transmissions, thus achieving higher system spectral efficiency.

[0090] In some implementations, during an R2D transmission, the reader is transmitting the R2D RF signal having a certain center frequency and bandwidth. In the meantime, a single tone CW signal at certain frequency offset from the center frequency of the R2D RF signal is also transmitted, either by the same reader as illustrated by FIG. 3A, or by a separate CW node as illustrated by FIG. 3B. As shown in FIG. 3A, a reader 304 transmits both the R2D signal and the CW signal simultaneously to an AIoT device 302. As shown in FIG. 3B, a separate CW node 316 is transmitting the CW signal while the reader 314 is transmitting the R2D signal to an AIoT device 312. The relationship between the frequency offset and the R2D signal bandwidth is described below in the disclosure.

[0091] In other implementations, a single reader 324 is transmitting multiple AIoT R2D signals using the FDM, and a single tone CW signal of certain frequency to AIoT devices 322, as illustrated in FIG. 3C. The AIoT device 322 can receive a particular R2D signal based on the frequency offset of the R2D signal from the CW signal.

[0092] In other implementations, a single reader 334 is transmitting multiple AIoT R2D signals using FDM to AIoT devices 332, and multiple CW nodes 336 separate from the reader are each transmitting a single tone CW signal of certain frequency as illustrated in FIG. 3D. The frequencies of the CW signals from the CW nodes 336 may be different from each other.

[0093] In other implementations, multiple readers 344 are deployed with overlapping coverage areas. Each reader 344 is transmitting the R2D RF signal of certain center frequency and bandwidth using different frequency resources to a respective AIoT device 342. A single tone CW signal corresponding to each reader 344 is transmitted by either the reader 344 as illustrated in FIG. 3E or a separate CW node. The frequency of the CW signal has a certain offset to its corresponding R2D signal. This frequency offset may be different for each reader.

[0094] The receiver may be implemented differently from the one in the reference architecture for Device 1. However, these differences are not expected to increase the power consumption of the receiver beyond the power budget of Device 1. For the purpose of this disclosure, the RF envelope detection receiver as described in the reference architecture for Device 1 may be referred to as the RFED receiver, and the receiver w ith the embodiments of new capability for in-band selectivity may be referred to as an enhanced RFED (RFED+) receiver. The RFED+ receiver can operate in two modes, namely a baseband mode (BB) and an intermediate frequency (IF) mode. The BB mode may also be understood as receiving an envelope of a signal w ith a frequency offset of zero. In the BB mode, the receiveroperates similarly to an RFED receiver. The IF mode may also be understood as receiving an envelope of a signal w ith a frequency offset not equal to zero. In the IF mode, the receiver is capable of in-band channel selectivity when an externally provided CW w ith the frequency offset to the R2D signal is present.

[0095] Devices with RFED capabilities suffer from interference due to FDM transmissions of other 5G NR signals and may not work when such transmissions are present. Devices with RFED+ capabilities can tolerate the interference from FDM transmissions of other 5G NR signals w hen an appropriate frequency of the CW is provided externally. The capability of a device to operate properly, e.g., in presence or absence of in-band interfering signals, is detailed in the following table.Table 1. Operations supported by the two types of devices

[0096] It is likely that some initial AIoT devices may only be equipped with an RFED receiver, and later versions will be equipped with an RFED+ receiver. In deployments, a mixture of both kinds of devices may be present at the same time. All of them can be addressable by the reader through the R2D link in TDM mode (without other FDM transmissions), regardless of the presence or absence of the CW. When an appropriate CW is present to the AIoT devices, the devices with RFED+ can be addressed by the reader with other FDM transmissions, including other AIoT R2D transmissions in different channels, and subsequently the system spectral efficiency can be significantly

[0097] To support devices with an RFED+ receiver, in one embodiment, the PHY packet header for the Physical Reader to Device Channel (PRDCH) includes one or more of the following fields (some optional) as shown in FIG. 4:• Data Rate: indicating the OOK data rate for the payload of the current packet. This field can be 2 or more bits.• Bandwidth: indicating the bandwidth of the R2D transmission. This field can be a spreading factor defined as the ratio between the number of subcarriers used for data modulation and the number of OOK bits per OFDM symbol. Alternatively, this field can also be an index to a table of pre-defined bandwidths. This field may be optional, as a fixed relationship between Bandwidth and Data Rate may be defined by the standards. This field can be 2 or more bits.• CW Configured (1 bit): for example, T indicating a single tone carrier wave is available for the device to use, ‘o’ indicating otherwise.• Frequency Offset: indicating the frequency separation between the single tone CW and the AIoT R2D signal. This field can be a ratio between the frequency offset and the bandwidth. Alternatively, this field can be an index to a table of pre-defined frequency offset values. This field may be optional, as a fixed relationship between Frequency Offset and the Data Rate (and Bandwidth) may be defined by the standards. This field be 2 or more bits.• Cyclic Redundancy Check (CRC): a CRC allows the packet header’s integrity to be checked. This field is optional.• Unused bits: A few unused bits before the starting of the payload provide a delay to allow the device time to process the header and adjust its operation accordingly. The bits are mapped into symbols the same way as the rest of the packet header. This field can be 0 or more bits. This field can be 0 bit, 1 bit, 2 bits, 3 bits, or 4 bits. The number of bits in this field is not limited to the embodiments described in this disclosure. In some implementations, the number of bits in this field may be based on the capability of the AIoT device.

[0098] In some implementations, setting CW Configured bit to “0” indicates to the devices equipped with RFED+ receivers of the absence of a CW, so that they can operate in the BB mode to receive the data packet in accordance with the indication. Setting CW Configured bit to “1” indicates to the devices equipped with RFED+ receivers of the presence of a CW, so that they can operate in the IF mode to receive the data packet even in the presence of other FDM transmissions in accordance with the indication. To accommodate the potential time needed by the AIoT devices to change its operationeither for a different data rate, or a different mode, optionally, a few unused bits can be reserved in the header right before the payload as shown in FIG. 4.

[0099] In an example deployment with a mixture of AIoT devices with RFED receiver and RFED+ receiver, for an example use case of inventory, the devices can be grouped into 2 groups. The first group includes dev ices with RFED receiver (no support of in- band channel selectivity). It also includes devices with RFED+ receiver at which the CW power is not strong enough to enable in-band channel selectivity. The second group includes the devices with RFED+ receiver that receive a strong enough CW signal to enable in-band channel selectivity. The reader does not know which device is in which group. However, various techniques can be used to take advantage of the in-band channel selectivity capability of the second group to increase the system spectral efficiency or throughput. An example strategy is that the reader can inventory the devices in the second group first by transmitting all packets in the R2D link with FDM of other signals and with CW configured, achieving high spectral efficiency. The devices in the second group are able to receive those R2D packets and respond accordingly to complete the inventory, owing to their in-band channel selectivity capability. Subsequently, the reader can inventory the devices in the first group by transmitting all R2D link packets without FDM of other signals. Those devices already inventoried will be configured to not respond during this period.

[0100] FIG. 5 illustrates, in one embodiment, the procedure the reader follows to send a message on R2D link. In FIGs. 5-7, the shaded boxes in the hatching pattern (e.g., box 502) are part of the procedures for deployment with only devices having RFED receivers, and the shaded boxes in the random-dot pattern (e.g., box 512) are part of the procedures for deployment w ith at least some devices having RFED+ receivers.

[0101] At the operation 502, the reader prepares a message to be sent to a set of targeted AIoT devices through the R2D link. The set of targeted AIoT devices can contain all devices (a broadcast message), or a sub-group of devices (for example, devices with RFED+ receivers), or just a single device (a unicast message).

[0102] If the targeted devices include devices with RFED receivers, the reader followsProcedure A to transmit the packet. At the operation 504, the reader determines the parameters for the target devices, such as the data rate and the bandwidth. At the operation 506, the reader sets the “CW Configured” bit to ‘0’ in the PHY header. At the operation 508, the reader assembles and modulates the PHY packet using the parameters determined at the operation 504. At the operation 510, the reader transmits the packet without other FDM transmissions.

[0103] If the targeted devices include only devices with RFED+ receivers and if not all the targeted devices are expected to support in-band channel selectivity (i.e., the CW signal received at the device is not strong enough to enable in-band channel selectivity), the reader follows Procedure A (operations 504-510) described above to transmit the packet.

[0104] If the targeted devices include only devices with RFED+ receivers and if the devices are expected to support in-band channel selectivity (i.e., the CW signal received at the device is strong enough to enable in-band channel selectivity), the reader follows Procedure B to transmit the packet. At the operation 512, the reader determines the parameters for the target devices, such as the data rate, the bandwidth, and the frequency offset. At the operation 514, the reader sets “CW Configured” bit to T in the PHY header. At the operation 516, the reader assembles and modulates the PHY packet using the parameters determined at the operation 512. At the operation 518, the reader configures and turns on CW at the CW node. At the operation 520, the reader transmits the packet without other FDM transmissions

[0105] In one embodiment, the AIoT device with the RFED receiver operates as usual, ignoring the CW related information in the header, as illustrated in FIG. 6 and described below.

[0106] At the operation 602, the AIoT device monitors the R2D link for messages. When a message is detected, the AIoT device reads the packet header first. When a packet header is received, the AIoT device uses the information in the packet header to receive the rest of the data packet at the operation 606. Alternatively, if a CRC is included in the header, the CRC is checked to confirm the validity of the packet header received.

[0107] In one embodiment, the AIoT device with the RFED+ device follows a procedure as illustrated in FIG. 7A. At the operation 702, the AIoT device starts to monitor the R2D link for data packets in both BB and IF mode simultaneously. The AIoT device reads the packet header first. This embodiment supports backward compatibility with readers that do not support RFED+ devices.

[0108] When a packet header is received from either in BB or IF mode at the operation 704, if the “CW configured” bit is set to T’, the AIoT device receives the rest of the data packet in the IF mode at the operation 708; otherwise, the AIoT device receives the rest of the data packet in in the BB mode at the operation 706. Alternativ ely, if a CRC is included in the header, the CRC is checked to confirm the validity of the packet header received.

[0109] In another embodiment, the AIoT device w ith the RFED+ receiver follows an alternate procedure as illustrated in FIG. 7B. At the operation 712, the AIoT device monitors the R2D link for data packets in the BB mode. The AIoT device reads the packet header first. When a packet header is received, if the “CW configured” bit is set to T, the AIoT device receives the rest of the data packet in the IF mode at the operation 718; otherwise, the AIoT device receives the rest of the data packet in the BB mode at the operation 716. Alternatively, if a CRC is included in the header, the CRC is checked to confirm the validity of the packet header received. In this embodiment, the packet header should not be transmitted with other FDM signals.

[0110] In another embodiment, the AIoT device with the RFED+ receiver follows an alternate procedure as illustrated in FIG. 7C. At the operation 722, the AIoT device monitors the R2D link for data packets in the IF mode. The AIoT device reads the packet header first. When a packet header is received, if the “CW configured” bit is set to T, the AIoT device receives the rest of the data packet in the IF mode; otherwise, the AIoT device receives the rest of the data packet in BB mode. Alternatively, if a CRC is included in the header, the CRC is checked to confirm the validity of the packet header received. In this embodiment, the reader with capability to support RFED+ receivers can announce such capability to the devices in a broadcast message, so that the devices with RFED+ receivers can switch to the procedure for receiving subsequent messages in a service session, such as an inventory session. Prior to receiving such broadcast message, the devices could follow either of the 2 procedures show n in FIG. 7A and FIG. 7B.

[0111] Table 2 summarizes the transmission options and reception options of the packet header. The reception options include the BB mode, the IF mode, or the simultaneous BB and IF mode as shown in FIGs. 7A-7B. The transmission options are with or without FDM transmission of other signals. It may be assumed that the FDMed other signals are sufficiently strong such that in-band selectivity is necessary for the reception of the header. Further, for both options, CW could be absent, sent by the reader together with the header, or sent by a separate CW node. For the case the CW is sent by CW node, it is assumed that the CW is sufficiently strong at the device to enable in-band selectivity. A device with the RFED receiver is only capable of reception in the BB mode.Table 2. Packet header transmission options and RFED+ capable device reception options[oii2] Table 3 summarizes the operation of device reception for the data packet following the header. The device that does not support RFED+ may ignore the CW configured field, while the device with RFED+ receiver switches between IF mode and BB mode depending on the CW configured field.Table 3. Reception mode of the device for data following the packet header

[0113] In another embodiment, the PRDCH packet may only contain a preamble and a payload. Within the payload, optional control information can be carried as part or entirety of the payload, as illustrated in FIG. 8. One or more of the following fields can be incorporated as part of the control information:• Data Rate: indicating the OOK data rate for the payload of the current packet.This field can be 2 or more bits.• Bandwidth: indicating the bandwidth of the R2D transmission. This field can be a spreading factor defined as the ratio between the number of subcarriers used for data modulation and the number of OOK bits per OFDM symbol. Alternatively, this field can also be an index to a table of pre-defined bandwidths. This field may be optional, as a fixed relationship between Bandwidth and Data Rate may be defined by the standards. This field can be 2 or more bits.• CW Configured (1 bit): for example, T indicating a single tone carrier wave is available for the device to use, ‘o’ indicating otherwise.• Frequency Offset: indicating the frequency separation between the single tone CW and the AIoT R2D signal. This field can be a ratio between the frequency offset and the bandwidth. Alternatively, this field can be an index to a table of pre-defined frequency offset values. This field may be optional, as a fixed relationship between Frequency Offset and the Data Rate (and Bandwidth) may be defined by the standards. This field can be 2 or more bits.• CRC: a CRC allows the integrity of the control information to be checked. This field is optional.• Unused bits: A few7unused bits before the rest of the payload provide a delay to allow7the device time to process the control information and adjust its operation accordingly. The bits are mapped into symbols the same way as the rest of the control information. This field can be 0 or more bits. This field can be 0 bit, 1 bit, 2 bits, 3 bits, or 4 bits. The number of bits in this field is not limited to the embodiments described in this disclosure. In some implementations, the number of bits in this field may be based on the capability of the AIoT device.

[0114] This control information may be contained in every PRDCH packet. To save overhead, this control information may also be sent only when needed. The AIoT device that receives this control information could assume the information to be valid for subsequent PRDCH packets it receives until the next set of control information is received, or conflicting control information is received.

[0115] In another example implementation, a polling procedure may be used by the reader to determine the type of AIoT devices under its coverage before subsequent communications. In an example, an AIoT device with the RFED receiver receives, in a first operation, a polling message in a BB mode. The polling message may be transmitted in a channel without any other FDM transmission or with a single tone CW as discussed below. In a second operation, the AIoT device responds to the polling message with an indication of an RFED receiver only capability. The indication may be explicit in the formof a message or implicit in the form of a random identifier selected from a set of identifiers used by AIoT devices w ith RFED receiver capability only. In a third operation, the AIoT device receives a data packet and detects a valid packet header in the BB mode. In a fourth operation, the AIoT device uses the BB mode to detect the data, e.g., information, in the received packet based on the detected packet header. The packet header may include information about any of the transmission / reception mode (i.e., BB mode or IF mode), a data rate, a modulation scheme / order, a coding scheme, a coding rate, a ban w idth, and a frequency offset.

[0116] In another example implementation, an AIoT device with the RFED+ receiver receives, in a first operation, a polling message in any of a BB mode and an IF mode. In a technical realization, the polling message may be transmitted in a channel w ithout any other FDM transmission as a default mode of operation and subsequently the BB mode should be used by default by the AIoT device. In another technical realization, the polling message may be transmitted in a channel with a single tone CW, as discussed below, as a default mode of operation and subsequently the IF mode should be used by default by the AIoT device. In a second operation, the AIoT device responds to the polling message w ith an indication of an RFED+ receiver capability. The indication may be explicit in the form of a message or implicit in the form of a random identifier selected from a set of identifiers used by AIoT devices with RFED+ receiver capability only. In a third operation, the AIoT device receives a data packet and detects a valid packet header in the IF mode. In a fourth operation, the AIoT device uses the IF mode to detect the data, e.g., information, in the received packet based on the detected packet header. Alternatively, the AIoT device uses BB mode to detect the data, e.g., information, in the received packet based on the detected packet header. The packet header may include information about any of the transmission / reception mode, i.e., BB or IF modes, a data rate, a modulation scheme / order, a coding scheme, a coding rate, a bandwidth, and a frequency offset.

[0117] FIG. 9A show’s a simplified block diagram of one embodiment of the RFED receiver in the reference architecture of FIG. 1F. The RF signal from antenna is detected at RF using an envelope detector. The envelope signal is passed through 2 filters with different bandwidths. Lowpass Filter 902 has low er bandwidth to extract the DC signal, and Lowpass Filter 901 has higher bandwidth to extract the R2D information. A comparator 903 converts the signals into a bit stream, which is decoded by the digital baseband circuit 904.

[0118] FIG. 9B illustrates the envelope detection process without any interference. At RF, the spectrum only contains the AIoT R2D RF signal. After envelope detection, the R2D envelope signal appears at the baseband frequencies.

[0119] In one embodiment, the CW is present during the R2D transmission to devices with RFED receivers, as illustrated in FIGs. 3A-3B. The following solution can be employed to mitigate the interference to the reception of the R2D data by the CW. FIG. 9C shows the RF spectrum of the AIoT R2D transmission in the presence of the carrier wave and the baseband spectrum of the signal after envelope detection. The separation between the carrier w ave frequency and the AIoT R2D signal is shown as / offset. The envelope signal contains primarily 3 parts, the self-mixing product of the carrier wave, which is the DC signal, the self-mixing product of the AIoT R2D signal, w hich is the desired AIoT R2D envelope signal, and the mixing product between the two, which is the RF AIoT DL signal frequency translated to IF and acts as interference. It is shown that if the / offset is greater than the bandwidth of the AIoT R2D signal, there is no overlap between the desired AIoT R2D envelope signal and the interfering signal, and the interference signal can be removed by the Low pass Filter 901. The effect of the DC bias produced by the carrier wave is mitigated by the Lowpass Filter 902 in FIG. 9A, as described above. The higher the offset relative to the R2D signal bandwidth, the easier the Lowpass Filter 901 is to implement. However, there is no need for / offsetto be too high, as it would use frequency resources unnecessarily.

[0120] FIG. 10A shows an exemplary and simplified block diagram of one embodiment of the RFED+ receiver. The RF signal from antenna is received at RF using a rectifier circuit 1012. The DC part of the output of the rectifier circuit 1012 can be sent to energy storage 1014 for powering the device. The rest is either processed either in the BB mode as show n by the BB mode dashed box 1020 in the FIG. 10A, or in IF mode passed through a DC removal and low pass filter circuit 1016. The output of the circuit 1016 is then envelope detected to obtain the baseband envelope signal of the R2D signal. The baseband envelope signal is filtered with 2 filters with different bandwidths.Low pass Filter 1002 has lower bandwidth to extract the DC signal, and Low pass Filter 1001 has higher bandwidth to extract the R2D information. A comparator 1003 converts the signals into a bit stream, which is decoded by the digital baseband circuit 1004.

[0121] FIG. 10B illustrates the detection process in the presence of a single tone CW and other FDM transmission. For the case illustrated in 3A, the single tone CW signal and the R2D signal are both transmitted by the reader (e.g., the CW emitter node and reader are co-located), w hile for the case illustrated in FIG. 3B, the single tone CW signal is transmitted by a CW node. For the case illustrated in FIG. 3C, the other signals in this figure represent another FDMed R2D signal. At RF, the spectrum contains the AIoT R2D RF signal, other signals at a different frequency, and the single tone CW at a power level higher than all the other signals. The CW signal is located at IF away from the R2Dsignal. After the rectification, which is equivalent to envelope detection, since the single tone CW is a high powered signal (compared to other signals in the received spectrum), its mixing product with all the other signals dominates the self-mixing products of all the other signals. Therefore, the CW acts as an LO in a heterodyne receiver and translates the spectrum to baseband, where the R2D signal appears at IF frequency. The self-mixing products of the R2D signal and other signals also appear at the baseband, but at much lower level. After DC removal and low power filtering, or alternatively bandpass filtering, only the R2D IF signal is remaining. It then goes through an envelope detection, after which the R2D envelope signal appears at the baseband frequencies. The interference from other signals, including FDM signals, is mitigated.

[0122] It may be assumed that the data rate of the header is known ahead of time by the targeted devices so that it can properly decode it through the following means:• a default rate that may be standardized;• a procedure is in place to inform the targeted device of the data rate of headers of subsequent packets.

[0123] When the targeted devices are all with RFED+ receiver, to take full advantage of the in-band selectivity and improve system spectral efficiency, it may be desirable to transmit the header with other FDM signals. In this case, the RFED+ receiver may need to be operating in the IF mode to receive the packet header properly. However, this approach may pose a problem if the RFED+ receivers are operating in the IF mode to receive packet header, yet the reader is transmitting packet without other FDM signals and without configuring CW. The devices will not be able to demodulate the packet header properly. To mitigate this problem, the reader can transmit a CW along with the R2D signal as illustrated in FIG. 11, so that the devices with RFED+ receiver operating in the IF mode can still demodulate the packet header, even if a CW is not configured or available at the device. As described above and illustrated in FIG. 9C, the RFED receivers are not impacted by this CW signal from the reader.

[0124] The / ir can be greater than the bandwidth of the AIoT R2D signal to avoid interference between baseband envelope of the AIoT signal and the mixing products between the carrier wave and the AIoT R2D signal.

[0125] In one embodiment, when greater system throughput is desired for AIoT services, multiple parallel AIoT channels can operate simultaneously on a single reader (e.g., BTS) to communicate with devices with RFED+ receiver assisted by multiple CW nodes with different coverage areas and different single tone CW frequencies as illustrated in FIG. 3D. It may be assumed that the coverage areas of the CW nodes arewit h i n the coverage area of the single reader. By the in-band selectivity afforded by the CW single tone acting as the LO, a device close to a CW node (e.g., its CW tone power dominates at the device) selects the channel next to the CW tone. In this way, the reader can simultaneously address multiple sets of devices under the coverage of different CW nodes w ith different messages specific to each set or individual devices within each set.

[0126] A detailed example is illustrated in FIG. 12 for Topology 1 with 2 CW nodes outside of the topology. In FIG. 12, there are 3 sets of devices: Set A 1202 under the coverage of CW node A with CW frequency assignment off A, Set B 1204 under the coverage of CW node B with CW frequency assignment of n, and Set C 1206 under the coverage of neither CW node A nor B. By the phrase “under the coverage of certain CW node,” this disclosure means that the powder of the CW signal from that particular CW node received by the device is much higher than other signals in the same RF band.

[0127] To transmit to Set A and Set B devices on the R2D link simultaneously with different messages, the reader transmits those messages on 2 separate R2D channels associated with the two CW node frequencies. Set A devices with the assistance of CW signal from CW node 1212 will only select the channel associated w ith \ and demodulate the message intended for Set A, while Set B devices with the assistance of CW signal from CW node 1214 will only select the channel associated with / Band demodulate the message intended for Set B. Thus, the system throughput is improved. Such messages can have their CW Configured Bit set to T.

[0128] However, for Set C 1206 devices, because they do not have the benefit of in- band channel selectivity, the reader has to transmit to them either by using a single channel, or by using the same message on both channels. The latter case may have the benefit of additional frequency diversity. Such messages can have their CW Configured Bit set to ‘o’.

[0129] A technical issue may arise as to how the reader knows w hich set a particular device belongs to. The reader can learn the association of the device with the CW node on the D2R link, when the device transmits through backscattering in response to broadcast from the reader. A broadcast message can be sent in such a way that all the devices can receive. For example, in the case illustrated in FIG. 12, the broadcast message can be sent on a single channel without CW configured and without other FDM signals, or the broadcast message can be sent simultaneously on both channels with CW configured, but still without other FDM signals, in order to reach all devices including Set C devices.

[0130] The devices respond by backscattering w hatever CW signals exist. A device’s response resolvable at the reader receiver will yield information about the device’sproximities to the CW nodes. A device under the coverage of CW node 1212 will have a much stronger D2R link signal show ing up at the reader receiver on a frequency associated w ith CW node 1212. Therefore, the BTS 1216 can place it in Set A 1202. If the D2R link signal from the device appear to be similar in strength at both frequencies, then it belongs to Set C 1206. This solution is illustrated in FIG. 12B.

[0131] FIG. 13 illustrates an example frequency resource allocation for simultaneous multi-channel AIoT operation w ith assistance from multiple single tone CW and coexistence with other 5G NR signals. In FIG. 13, the separation between the AIoT R2D signals can be at least 3 times the bandwidth of the R2D signal such that w hen the RF signal is mixing with the dominant CW tone in the envelope detection or rectification process, there will not be interference from images. The greater the separation, the easier to eliminate any interference with baseband filtering. In FIG. 13, the carrier wave tone can be separated from its corresponding R2D signal by at least the R2D signal bandwidth. In FIG. 13, guardbands can exist between the R2D signal and other NR signal to ease the baseband filtering. In FIG. 13, the offsets between the AIoT R2D signals and their corresponding CW signals may or may not be the same. Having different offsets provides even more isolation between the multiple R2D signals at the device after envelope detection, as the multiple parallel R2D signals will appear at different intermediate frequencies.

[0132] In another embodiment, without standalone CW nodes, a reader (e.g., a BTS in Topology 1 or an intermediate node in Topology 2) can increase its system throughput by sending parallel AIoT R2D channels and a single tone high power carrier wave signal to AIoT devices w ith RFED+ receivers as illustrated in FIG. 3C. A detailed example w ith 2 parallel AIoT R2D channels is illustrated in FIGs. 14A and 14B for the case of Topology 1. In FIG. 14A, the RF spectrum of the reader transmission is illustrated. A high power single tone carrier wave signal and two R2D channels are transmitted simultaneously. The frequency offsets for the two R2D channels to the CW are \ and / iS, respectively. As illustrated in FIG. 14B, the AIoT devices are assigned to communicate on either of the two R2D channels. This could be done through control messages informing the devices to choose a channel either randomly or according to their ID or other parameters. The devices could then operate in the IF mode with its chosen or assigned frequency offset. In this way, the reader (e.g., BTS) can communicate simultaneously with two groups of devices on two separate R2D channels.

[0133] A technical issue may be raised about the R2D link range in this case as most of the RF power is used to transmit CW signal. In the case where the AIoT devices are powered up by energy harvesting the RF power, the R2D link range is usually limited bythe required total RF power received at the device for energy harvesting, rather than the receiver sensitivity for the R2D signal. Therefore, a significant portion of the total RF signal can be dedicated to the CW signal to enable simultaneous multi-channel operations with higher system throughput.

[0134] In another embodiment involving multiple readers without standalone CW nodes, multiple readers can leverage such channel selectivity of AIoT devices with RFED+ receiver to mitigate interference problems for devices in the overlapping coverage areas of the readers as illustrated in FIG. 3E. The readers can be base stations as in Topology 1, or intermediate nodes as in Topology 2. To illustrate the interference problem, there may be two readers with an overlapping coverage area. AIoT devices in the overlapping coverage area receive the R2D signals from the two readers with similar power levels. Regardless of the frequency channels used by the two readers, the envelope detector in the AIoT device cannot differentiate the two R2D signals. As a result, the two R2D signals interfere with each other and prevent either being demodulated by the receiver. However, if each of the 2 readers also sends out a single tone CW signal with different offset to their respective R2D channel, and the R2D channel frequencies are chosen appropriately, as illustrated in FIGs. 15A and 15B. The AIoT devices with RFED+ receiver w ill be able to differentiate the two R2D channels, thus mitigating the interference problem.

[0135] FIG. 15A shows the transmit spectrum of the two readers. The two frequency offsets / A and / n have to be greater than the bandwidth of its corresponding R2D channel, and their difference has to be greater than the bandwidth of the wider R2D channel. The frequency separation of the two R2D channels / ^p, should be sufficiently large, such that the intermixing products of the two readers’ signals after envelope detection fall outside of the intermediate frequency range of interest. FIG. 15B illustrate the coverage of the two readers. The area denoted by the dashed circle is the overlapping coverage area of the two readers. An AIoT device in this area receives R2D transmissions from both readers at similar power levels. However, the envelope detection process converts the R2D signals from the two readers at two intermediate frequencies of / k and p, respectively. If the device is informed already of its channel assignment, it can then demodulate the appropriate channel without interference.

[0136] FIG. 16A shows a flow chart of a method 1600 performed by a wireless device (e.g., a wireless transmit / receive unit (WTRU)), in accordance with some implementations. The wireless device may include computer-readable code or instructions executing on one or more processors of the wireless device. Coding of the software for carrying out or performing the method 1600 is well within the scope of aperson of ordi naty skill in the art having regard to the present disclosure. The method 1600 may include additional or fewer operations than those show n and described and may be carried out or performed in a different order. Computer-readable code or instructions of the software executable by the one or more processors may be stored on at least one non-transitoiy computer-readable medium, such as for example, at least one memoiy of the wireless device. In some embodiments, the method 1600 may be performed by one or more of units or modules (e.g., an integrated circuit) of the wireless device, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0137] The method 1600 starts at the operation 1602, where the WTRU receives a carrier wave (CW). At the operation 1604, the WTRU receives an Ambient Internet of Things (AIoT) Reader to Device (R2D) signal associated with the CW. At least a portion of the AIoT R2D signal and the CW are received simultaneously.

[0138] In some implementations, the WTRU may receive control information. The WTRU may receive a payload of a data packet in the AIoT R2D signal following the control information. The WTRU may demodulate the payload of the data packet based on the control information and the CW.

[0139] In some implementations, the control information may be in a packet header of the data packet before the payload of the data packet.

[0140] In some implementations, the control information may be in the payload of the data packet following a preamble of the data packet.

[0141] In some implementations, the control information may be in a second data packet different from the data packet.

[0142] In some implementations, the control information may indicate that the data packet is configured to be received using the CW.

[0143] In some implementations, the control information may indicate a frequency offset between the CW and the AIoT R2D signal.

[0144] In some implementations, the frequency offset may be greater than a bandwidth of the AIoT R2D signal and less than 3 times the bandwidth of the AIoT R2D signal.

[0145] In some implementations, the frequency offset may be at least 3 times a bandwidth of the AIoT R2D signal.

[0146] In some implementations, the frequency offset may be between the CW and a center frequency of the AIoT R2D signal.

[0147] Insome implementations, the control information may further indicate a data rate of the data packet and a bandwidth of the AIoT R2D signal.

[0148] In some implementations, the control information may be received in a first envelope of a first signal with a first frequency offset of 0 in a baseband (BB) mode. The payload of the data packet may be received in a second envelope of a second signal with a second frequency offset not equal to o in an intermediate frequency (IF) mode.

[0149] In some implementations, the control information may be time division multiplexed (TDMed) with a first signal intended for another terminal device. The payload of the data packet may be frequency division multiplexed (FDMed) with a second signal. The second signal may be the same as or different from the first signal.

[0150] In some implementations, the CW may include a single tone signal.

[0151] In some implementations, the WTRU may receive a second signal requesting a device capability. The WTRU may transmit an indication of a capability of a receiver of the WTRU supporting in-band selectivity.

[0152] In some implementations, a payload of a data packet in the AIoT R2D signal may be received simultaneously with the CW.

[0153] FIG. 16B shows a flow chart of a method 1650 performed by a system on the network side (e.g., a network system), in accordance w ith some implementations. The network system may include computer-readable code or instructions executing on one or more processors of the network system. Coding of the software for carrying out or performing the method 1650 is well within the scope of a person of ordinary skill in the art having regard to the present disclosure. The method 1650 may include additional or fewer operations than those shown and described and may be carried out or performed in a different order. Computer-readable code or instructions of the software executable by the one or more processors may be stored on at least one non-transitoiy computer- readable medium, such as for example, at least one memory of the network system. In some embodiments, the method 1650 may be performed by one or more of units or modules (e.g., an integrated circuit) of the network system, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0154] The method 1650 starts at the operation 1652, where the network system transmits a carrier wave (CW). At the operations 1654, the network system transmits an Ambient Internet of Things (AIoT) Reader to Device (R2D) signal associated with the CW. At least a portion of the AIoT R2D signal and the CW are transmitted simultaneously.

[0155] In some implementations, at least a portion of the AIoT R2D signal and theCW may be transmitted simultaneously.

[0156] In some implementations, the AIoT R2D signal may be transmitted by a reader device of the network system. The CW may be transmitted by a CW node of the network system different from the reader device.

[0157] In some implementations, the CW and the AIoT R2D signal associated with the CW may be transmitted to a wireless transmit / receive unit (WTRU).

[0158] In some implementations, the network system may transmit control information to a WTRU. The network system may transmit a payload of a data packet in the AIoT R2D signal following the control information. The control information may be used by the WTRU to demodulate the payload of the data packet.

[0159] In some implementations, the control information may be in a packet header of the data packet before the payload of the data packet.

[0160] In some implementations, the control information may be in the payload of the data packet following a preamble of the data packet.

[0161] In some implementations, the control information may be in a second data packet different from the data packet.

[0162] In some implementations, the control information may indicate that the data packet is configured to be received using the CW.

[0163] In some implementations, the control information may indicate a frequency offset between the CW and the AIoT R2D signal.

[0164] In some implementations, the frequency offset may be greater than a bandwidth of the AIoT R2D signal and less than 3 times the bandwidth of the AIoT R2D signal.

[0165] In some implementations, the frequency offset may be at least 3 times a bandwidth of the AIoT R2D signal.

[0166] In some implementations, the frequency offset may be between the CW and a center frequency of the AIoT R2D signal.

[0167] In some implementations, the control information may further indicate a data rate of the data packet and a bandwidth of the AIoT R2D signal.

[0168] In some implementations, the control information may be time division multiplexed (TDMed) with a first signal intended for another terminal device. Thepayload of the data packet may be frequency division multiplexed (FDMed) with a second signal. The second signal may be the same as or different from the first signal.

[0169] In some implementations, the CW may include a single tone signal.

[0170] In some implementations, the network system may transmit to a WTRU a second signal requesting a device capability. The network may receive an indication of a capability of a receiver of the WTRU supporting in-band selectivity.

[0171] In some implementations, a payload of a data packet in the AIoT R2D signal may be transmitted simultaneously with the CW.

[0172] This following references are incorporated by reference in this disclosure.[1] 3GPP RP-234058, New SID: Study on solutions for Ambient loT (Internet of Things) in NR, Huawei, Dec 2023[2] 3GPP TR 38.848, Study on Ambient loT (Internet of Things) in RAN, Release 18, 2023[3] 3GPP R1-2401835 Final FL summary #4 FOR 9.4.1.2 Ambient loT Device Architecture, March 2024

[0173] The network system described in this disclosure may include a network node or a plurality of network nodes each configured to perform at least one of the network side operations described above. For example, a first network node of the network system may transmit the CW. A second network node of the netw ork system may transmit the AIoT R2D signal. The first network node or the second network node may be the same or different from each other. The network side operations may be distributed among different network nodes in any combination or configuration, without limitation to the specific examples provided herein.

[0174] FIG. 17 illustrates an example communications system 1700. Communications system 1700 includes an access node 1710 serving user equipments (UEs) with coverage 1701, such as UEs 1720. In a first operating mode, communications to and from a UE passes through access node 1710 with a coverage area 1701. The access node 1710 is connected to a backhaul network 1715 for connecting to the internet, operations and management, and so forth. In a second operating mode, communications to and from a UE do not passthrough access node 1710, however, access node 1710 ty pically allocates resources used by the UE to communicate w hen specific conditions are met.Communications between a pair of UEs 1720 can use a sidelink connection (shown as two separate one-w ay connections 1725). In FIG. 17, the sidelink communication is occurring between two UEs operating inside of coverage area 1701. However, sidelink communications, in general, can occur w hen UEs 1720 are both outside coverage area1701, both inside coverage area 1701, or one inside and the other outside coverage area 1701. 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 1730, and the communication links between the access node and UE is referred to as downlinks 1735.

[0175] 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 w ith 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.

[0176] FIG. 18 illustrates an example communication system 1800. In general, the system 1800 enables multiple wireless or wired users to transmit and receive data and other content. The system 1800 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).

[0177] In this example, the communication system 1800 includes electronic devices (ED) i8ioa-i8ioc, radio access networks (RANs) t82oa-i82ob, a core network 1830, a public switched telephone network (PSTN) 1840, the Internet 1850, and other networks i860. While certain numbers of these components or elements are shown in FIG. 18, any number of these components or elements may be included in the system 1800.

[0178] The EDs i8toa-i8toc are configured to operate or communicate in the system 1800. For example, the EDs t8ioa-i8toc are configured to transmit or receive via wireless or wired communication channels. Each ED t8ioa-i8ioc 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, AIoT device (e.g., for asset management), or consumer electronics device.

[0179] The RANs i82oa-i82ob here include base stations lSyoa-iSyob, respectively. Each base station 1870a- 1870b is configured to wirelessly interface w ith one or more of the EDs i8ioa-i8ioc to enable access to the core network 1830, the PSTN 1840, the Internet 1850, or the other networks i860. For example, the base stations i870a-i870b 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 i8ioa-i8ioc are configured to interface and communicate with the Internet 1850 and may access the core network 1830, the PSTN 1840, or the other networks i860.

[0180] In the embodiment shown in FIG. 18, the base station 1870a forms part of the RAN 1820a, which may include other base stations, elements, or devices. Also, the base station 1870b forms part of the RAN 1820b, which may include other base stations, elements, or devices. Each base station i870a-i870b 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.

[0181] The base stations i87oa-i87ob communicate with one or more of the EDs i8ioa-i8ioc over one or more air interfaces 1890 using wireless communication links. The air interfaces 1890 may utilize any suitable radio access technology.

[0182] It is contemplated that the system 1800 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.

[0183] The RANs i82oa-i82ob are in communication with the core network 1830 to provide the EDs t8ioa-i8ioc with voice, data, application, Voice over Internet Protocol (VoIP), or other services. Understandably, the RANs i82oa-i82ob or the core network 1830 may be in direct or indirect communication with one or more other RANs (not shown). The core network 1830 may also serve as a gateway access for other networks (such as the PSTN 1840, the Internet 1850, and the other networks i860). In addition, some or all of the EDs i8ioa-i8ioc 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), theEDs may communicate via wired communication channels to a sendee provider or sw itch (not shown), and to the Internet 1850.

[0184] Although FIG. 18 illustrates one example of a communication system, various changes may be made to FIG. 18. For example, the communication system 1800 could include any number of EDs, base stations, networks, or other components in any suitable configuration.

[0185] FIGs. 19A and 19B illustrate example devices that may implement the methods and teachings according to this disclosure. In particular, FIG. 19A illustrates an example ED 1910, and FIG. 19B illustrates an example base station 1970. These components could be used in the system 1800 or in any other suitable system.

[0186] As shown in FIG. 19A, the ED 1910 includes at least one processing unit 1900. The processing unit 1900 implements various processing operations of the ED 1910. For example, the processing unit 1900 could perform signal coding, data processing, power control, input / output processing, or any other functionality enabling the ED 1910 to operate in the system 1800. The processing unit 1900 also supports the methods and teachings described in more detail above. Each processing unit 1900 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 1900 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

[0187] The ED 1910 also includes at least one transceiver 1902. The transceiver 1902 is configured to modulate data or other content for transmission by at least one antenna or NIC (Network Interface Controller) 1904. The transceiver 1902 is also configured to demodulate data or other content received by the at least one antenna 1904. Each transceiver 1902 includes any suitable structure for generating signals for wireless or wired transmission or processing signals received wirelessly or by wire. Each antenna 1904 includes any suitable structure for transmitting or receiving wireless or wired signals. One or multiple transceivers 1902 could be used in the ED 1910, and one or multiple antennas 1904 could be used in the ED 1910. Although shown as a single functional unit, a transceiver 1902 could also be implemented using at least one transmitter and at least one separate receiver.

[0188] The ED 1910 further includes one or more input / output devices 1906 or interfaces (such as a wired interface to the Internet 1850). The input / output devices 1906 facilitate interaction with a user or other devices (network communications) in the network. Each input / output device 1906 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.

[0189] In addition, the ED 1910 includes at least one memory' 1908. The memory' 1908 stores instructions and data used, generated, or collected by the ED 1910. For example, the memory' 1908 could store software or firmware instructions executed by the processing unit(s) 1900 and data used to reduce or eliminate interference in incoming signals. Each memory 1908 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 identitymodule (SIM) card, memory stick, secure digital (SD) memory card, and the like.

[0190] As shown in FIG. 19B, the base station 1970 includes at least one processing unit 1950, at least one transceiver 1952, which includes functionality for a transmitter and a receiver, one or more antennas 1956, at least one memory’ 1958, and one or more input / output devices or interfaces 1966. A scheduler, which would be understood by one skilled in the art, is coupled to the processing unit 1950. The scheduler could be included within or operated separately from the base station 1970. The processing unit t95O implements various processing operations of the base station 1970, such as signal coding, data processing, power control, input / output processing, or any other functionality. The processing unit 1950 can also support the methods and teachings described in more detail above. Each processing unit 1950 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 1950 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

[0191] Each transceiver 1952 includes any suitable structure for generating signals for wireless or wired transmission to one or more EDs or other devices. Each transceiver 1952 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 1952, a transmitter and a receiver could be separate components. Each antenna 1956 includes any suitable structure for transmitting or receiving wireless or wired signals. While a common antenna 1956 is shown here as being coupled to the transceiver 1952, one or more antennas 1956 could be coupled to the transceiver(s) 1952, allowing separate antennas 1956 to be coupled to the transmitter and the receiver if equipped as separate components. Each memoiy 1958 includes any suitable volatile or non-volatile storage and retrieval device(s). Each input / output device 1966 facilitates interaction with a user or other devices (network communications) in the network. Each input / output device 1966 includes any suitable structure for providing information to or receiving / providing information from a user, including network interface communications.

[0192] FIG. 20 is a block diagram of a computing system 2000 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 vary from device to device. Furthermore, a device may contain multiple instances of a component, such as multiple processing units, processors, memories, transmitters, receivers, etc. The computing system 2000 includes a processing unit 2002. The processing unit includes a central processing unit (CPU) 2014, memoiy 2008, and may further include a mass storage device 2004, a video adapter 2010, and an I / O interface 2012 connected to a bus 2020.

[0193] The bus 2020 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 2014 may comprise any type of electronic data processor. The memoiy 2008 may comprise any type of non-transitory system memory such as static random access memoiy (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memoiy (ROM), or a combination thereof. In an embodiment, the memoiy 2008 may include ROM for use at boot-up, and DRAM for program and data storage for use while executing programs.

[0194] The mass storage 2004 may comprise any type of non-transitory storage device configured to store data, programs, and other information and to make the data, programs, and other information accessible via the bus 2020. The mass storage 2004 may comprise, for example, one or more of a solid state drive, hard disk drive, a magnetic disk drive, or an optical disk drive.

[0195] The video adapter 2010 and the I / O interface 2012 provide interfaces to couple external input and output devices to the processing unit 2002. As illustrated, examples of input and output devices include a display 2018 coupled to the video adapter 2010 and a mouse, keyboard, or printer 2016 coupled to the I / O interface 2012. Other devices may be coupled to the processing unit 2002, 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.

[0196] The processing unit 2002 also includes one or more network interfaces 2006, which may comprise wired links, such as an Ethernet cable, or wireless links to access nodes or different networks. The network interfaces 2006 allow the processing unit 2002 to communicate with remote units via the networks. For example, the network interfaces 2006 may provide wireless communication via one or more transmitters / transmit antennas and one or more receivers / receive antennas. In an embodiment, the processingunit 2002 is coupled to a local-area network 2022 or a w ide-area network for data processing and communications with remote devices, such as other processing units, the Internet, or remote storage facilities.

[0197] It should be appreciated that not all components in the devices described in FIG. 17-20 are required. In a non-limiting example, the ED 1910 may be implemented as an AIoT device 1910. But, the AIoT device 1910 may not include an input / output devices 1906 for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen. The transceiver 1902 of the AIoT device 1910 may be capable of transmitting by backscattering a radio wave received, instead of by generating the radio wave, for wireless communication purpose. In another non-limiting example, the system 2000 may be implemented as an AIoT device 2000 that does not include or use the mass storage device 2004, the video adapter 2010, the mouse, keyboard, or printer 2016, or the display 2018.

[0198] 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).

[0199] 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 within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claims

What Is Claimed Is:

1. A method, comprising: receiving, by a wireless transmit / receive unit (WTRU), a carrier wave (CW); and receiving, by the WTRU, an Ambient Internet of Things (AIoT) Reader to Device (R2D) signal associated with the CW, wherein at least a portion of the AIoT R2D signal and the CW are received simultaneously.

2. The method of claim 1, the receiving the AIoT R2D signal comprising: receiving control information; receiving a payload of a data packet in the AIoT R2D signal follow ing the control information; and demodulating the payload of the data packet based on the control information and the CW.

3. The method of claim 2, the control information being in a packet header of the data packet before the payload of the data packet.

4. The method of any of claims 2-3, the control information being in the payload of the data packet following a preamble of the data packet.

5. The method of any of claims 2-4, the control information being in a second data packet different from the data packet.

6. The method of any of claims 2-5, the control information indicating that the data packet is configured to be received using the CW.

7. The method of any of claims 2-6, the control information indicating a frequency offset between the CW and the AIoT R2D signal.

8. The method of claim 7, the frequency offset being greater than a bandwidth of the AIoT R2D signal and less than 3 times the band width of the AIoT R2D signal.

9. The method of claim 7, the frequency offset being at least 3 times a bandwidth of the AIoT R2D signal. to. The method of claim 7, the frequency offset being between the CW and a center frequency of the AIoT R2D signal.

11. The method of any of claims 2-10, the control information further indicating a data rate of the data packet and a bandw idth of the AIoT R2D signal.

12. The method of claims 2-11, w herein the control information is received in a first envelope of a first signal with a first frequency offset of 0 in a baseband (BB) mode, and the payload of the data packet is received in a second envelope of a second signal with a second frequency offset not equal to o in an intermediate frequency (IF) mode.

13. The method of any of claims 2-12, wfierein the control information is time division multiplexed (TDMed) with a first signal intended for another terminal device, and the payload of the data packet is frequency division multiplexed (FDMed) with a second signal, the second signal being the same as or different from the first signal.

14. The method of any of claims 1-13, wherein the CW includes a single tone signal.

15. The method of any of claims 1-14, further comprising: receiving a second signal requesting a device capability; and transmitting an indication of a capability of a receiver of the WTRU supporting in-band selectivity.

16. The method of any of claims 1-15, wherein all of the AIoT R2D signal is received simultaneously with the CW.

17. The method of any of claims 1-16, wherein a payload of a data packet in the AIoT R2D signal is received simultaneously with the CW.

18. A method, comprising: transmitting, by a network system, a carrier wave (CW); and transmitting, by the network system, an Ambient Internet of Things (AIoT) Reader to Device (R2D) signal associated with the CW, wherein at least a portion of the AIoT R2D signal and the CW are transmitted simultaneously.

19. The method of claim 18, wherein the AIoT R2D signal and the CW associated with the CW are transmitted by a reader device of the network system.

20. The method of any of claims 18-19, w herein the AIoT R2D signal is transmitted by a reader device of the network system, and the CW is transmitted by a CW node of the network system different from the reader device.

21. The method of any of claims 18-20, wherein the CW and the AIoT R2D signal associated with the CW are transmitted to a wireless transmit / receive unit (WTRU).

22. The method of claim 18, the transmitting the AIoT R2D signal comprising: transmitting, to a WTRU, control information; and transmitting, to the WTRU, a payload of a data packet in the AIoT R2D signal following the control information, the control information used by the WTRU to demodulate the payload of the data packet.

23. The method of claim 22, the control information being in a packet header of the data packet before the payload of the data packet.

24. The method of any of claims 22-23, the control information being in the payload of the data packet following a preamble of the data packet.

25. The method of any of claims 22-24, the control information being in a second data packet different from the data packet.

26. The method of any of claims 22-25, the control information indicating that the data packet is configured to be received using the CW.

27. The method of any of claims 22-26, the control information indicating a frequency offset between the CW and the AIoT R2D signal.

28. The method of claim 27, the frequency offset being greater than a bandwidth of the AIoT R2D signal and less than 3 times the bandwidth of the AIoT R2D signal.

29. The method of claim 27, the frequency offset being at least 3 times a bandwidth of the AIoT R2D signal.

30. The method of claim 27, the frequency offset being between the CW and a center frequency of the AIoT R2D signal.

31. The method of any of claims 22-30, the control information further indicating a data rate of the data packet and a bandwidth of the AIoT R2D signal.

32. The method of any of claims 22-31, wherein the control information is time division multiplexed (TDMed) with a first signal intended for another terminal device, and the payload of the data packet is frequency division multiplexed (FDMed) with a second signal, the second signal being the same as or different from the first signal.33- The method of any of claims 18-32, wherein the CW includes a single tone signal.

34. The method of any of claims 18-33, further comprising: transmitting, to a WTRU, a second signal requesting a device capability; and receiving an indication of a capability of a receiver of the WTRU supporting in- band selectivity.

35. The method of any of claims 18-34, wherein all of the AIoT R2D signal is transmitted simultaneously with the CW.

36. The method of any of claims 18-35, wherein a payload of a data packet in the AIoT R2D signal is transmitted simultaneously with the CW.

37. A wireless transmit / receive unit (WTRU), 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 WTRU to perform a method according any of claims 1-17.

38. A network system, comprising: at least one processor; and at least one non-transitoiy computer readable storage medium storing programming, the programming including instructions that, when executed by the at least one processor, cause the network system to perform a method according any of claims 18-36.

39. A non-transitoiy computer-readable medium having instructions stored thereon that, when executed by a wireless transmit / receive unit (WTRU), cause the WTRU to perform a method according any of claims 1-17.

40. At least one non-transitoiy computer-readable medium having instructions stored thereon that, when executed by a network system, cause the network system to perform a method according any of claims 18-36.

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