Derivative works

Defensive Disclosure: Enhancements and Alternative Embodiments for Non-Contiguous Channel Access in Wireless Networks

Publication Date: May 14, 2026
Reference Patent: US 10,687,281 B2
Inventors: Advanced Research Team
Assignee: Open Standard Advancement Corporation

Abstract: This document discloses several novel methods, systems, and applications related to wireless communication over non-contiguous frequency channels. The disclosed embodiments expand upon the techniques described in US Patent 10,687,281 by introducing alternative materials for RF components, extending operational parameters to new environments, applying the core concepts to diverse industries, integrating with emerging technologies like AI/ML, and defining fail-safe operational modes. The purpose of this disclosure is to place these derivative concepts into the public domain, thereby creating prior art to foster innovation and prevent unduly broad patenting in this technological space.

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Claim 1: Non-Contiguous Channel Reception

Derivative 1: Material & Component Substitution

• 1.1 Graphene-based Tunable RF Filters:

  • Enabling Description: The wireless communication terminal's front-end receiver, responsible for processing the received packet, incorporates a Graphene-based Radio Frequency (RF) filter. Instead of traditional fixed-frequency SAW/BAW filters, this design uses a dynamically tunable filter array. The non-contiguous channel allocation information, once decoded from the HE-SIG-A/B fields, is passed to a filter control processor. This processor applies a variable gate voltage to specific graphene resonator elements in the filter array. The applied voltage alters the carrier density in the graphene, thereby shifting the resonant frequency of each filter element. This allows the receiver to rapidly reconfigure its passband to match the specific non-contiguous sub-channels indicated in the packet's preamble, effectively nullifying interference from the "punctured" or unused channels. This provides superior out-of-band rejection compared to wider, fixed-filter designs and improves SNR for the active sub-channels.
  • Mermaid Diagram:

    graph TD
        A[Antenna] --> B(Graphene Tunable Filter Array);
        B --> C{RF Front-End};
        C --> D[Baseband Processor];
        D --> E{Preamble Decoder};
        E -- HE-SIG A/B Info --> F(Filter Control Processor);
        F -- Gate Voltages --> B;
        D -- Decoded Data --> G[Upper Layers];
    

• 1.2 Silicon-Germanium (SiGe) BiCMOS Integrated Front-End:

  • Enabling Description: The entire RF front-end, including the Low-Noise Amplifier (LNA) and mixer, is implemented using a Silicon-Germanium Bipolar CMOS (SiGe BiCMOS) process. This allows for higher electron mobility and lower noise figures at the 5/6 GHz bands compared to standard CMOS. For non-contiguous channel reception, the baseband processor, upon decoding the channel allocation from the preamble, directly controls a parallel bank of SiGe LNAs. Each LNA is optimized for a specific 20 MHz sub-channel. The processor activates only the LNAs corresponding to the allocated channels, keeping the others in a low-power state. This component-level power gating, enabled by the fast switching characteristics of SiGe transistors, reduces power consumption and minimizes thermal noise contribution from inactive receiver chains.
  • Mermaid Diagram:

    sequenceDiagram
        participant Antenna
        participant LNA_Bank
        participant Mixer
        participant ADC
        participant Baseband
        Antenna->>LNA_Bank: Receives wideband signal
        Baseband->>LNA_Bank: Activate LNA for Ch1, Ch3
        LNA_Bank->>Mixer: Pass-through filtered Ch1, Ch3 signals
        Mixer->>ADC: Downconvert signals
        ADC->>Baseband: Digitized I/Q data
        Baseband->>Baseband: Decode HE-SIG, determine Ch1, Ch3 are active
    

• 1.3 Metamaterial-based Antenna for Spatial Filtering:

  • Enabling Description: The terminal uses a reconfigurable metamaterial-based antenna array. The physical properties of the metamaterial elements (e.g., split-ring resonators) can be altered electronically. When the processor decodes the non-contiguous channel information, it also cross-references a database of known local interference sources. An algorithm then calculates the optimal antenna radiation pattern to create spatial nulls in the direction of interfering devices that may be operating in the punctured channels. This spatial filtering complements the frequency-domain filtering, providing an additional layer of interference rejection, which is particularly useful in dense Wi-Fi environments.
  • Mermaid Diagram:

    graph TD
        subgraph Terminal
            A[Preamble Decoder] -- Channel Map --> B(Beamforming Controller);
            C[Interference DB] --> B;
            B -- Element Phases/Amplitudes --> D{Metamaterial Antenna Array};
        end
        E(Incoming RF Signal) --> D;
        D -- Focused Signal --> F(Receiver);
    

Derivative 2: Operational Parameter Expansion

• 2.1 Cryogenic/High-Temperature Operation:

  • Enabling Description: The communication terminal is designed for operation in extreme temperature environments (-200°C to +150°C), such as in space-based communication systems or industrial process control. The processor and RF components are fabricated using Silicon on Insulator (SOI) or Gallium Nitride (GaN) technologies, which offer superior thermal stability. The logic for decoding the HE-SIG-B and configuring the RF front-end is hardened against temperature-induced clock drift and bit errors. The non-contiguous channel allocation algorithm in the base station is adapted to account for temperature-dependent variations in channel noise floors across the wideband spectrum, selectively puncturing channels that exhibit high thermal noise.
  • Mermaid Diagram:

    stateDiagram-v2
        [*] --> Idle
        state "Environment Scan" as Scan {
            [*] --> TempCheck
            TempCheck --> HighTemp: > 100C
            TempCheck --> LowTemp: < -50C
            TempCheck --> Nominal: else
        }
        Idle --> Scan: On Power-Up
        HighTemp --> Puncture_Hot_Channels
        LowTemp --> Puncture_Noisy_Channels
        Nominal --> Standard_CCA
        Puncture_Hot_Channels --> Transmit
        Puncture_Noisy_Channels --> Transmit
        Standard_CCA --> Transmit
        Transmit --> Idle
    

• 2.2 Terahertz (THz) Band Non-Contiguous Operation:

  • Enabling Description: The principles of non-contiguous channel allocation are applied to the sub-terahertz frequency bands (100-300 GHz). At these frequencies, atmospheric absorption creates natural "notches" or high-attenuation windows in the spectrum. The base station (AP) performs a "spectral absorption scan" in addition to a standard CCA. It then uses the HE-SIG-A/B structure, adapted for THz frame formats, to signal a channel map that punctures these known absorption bands. This avoids wasting power on transmitting through unusable frequencies and allows the receiver to bypass those channels, simplifying the RF front-end design and improving the overall link budget.
  • Mermaid Diagram:

    graph TD
        A[AP: THz Band Scan] --> B{Identify Absorption Bands};
        B --> C{Generate Puncturing Mask};
        C --> D[Encode Mask in THz-SIG Field];
        D --> E[Transmit THz PPDU];
        F[STA: Receive THz PPDU] --> G{Decode THz-SIG};
        G --> H[Extract Puncturing Mask];
        H --> I[Configure Receiver for Non-Contiguous Channels];
        I --> J[Decode Data];
    

• 2.3 High-Doppler (Vehicular) Environments:

  • Enabling Description: In a vehicle-to-everything (V2X) context, high Doppler shifts can cause significant inter-carrier interference (ICI) in OFDM systems. This method adapts the non-contiguous channel allocation to mitigate Doppler effects. The base station estimates the Doppler spread for a moving vehicle. It then intentionally punctures the sub-channels at the edges of each 20 MHz block, which are most susceptible to ICI. The HE-SIG-B's Resource Unit (RU) allocation field is used to signal this sub-channel level puncturing, indicating that edge-located RUs (e.g., 26-tone RUs) are nulled. This creates wider guard bands between the active data-carrying sub-channels, improving demodulation robustness in high-mobility scenarios.
  • Mermaid Diagram:

    gantt
        title Non-Contiguous Transmission in High-Doppler V2X
        dateFormat  X
        axisFormat %s
    
        section AP (Roadside Unit)
        Estimate Doppler :a1, 0, 2ms
        Select Guard-Band RUs :a2, 2, 4ms
        Generate HE-SIG-B :a3, 4, 5ms
        Transmit PPDU :a4, 5, 10ms
    
        section Vehicle (STA)
        Receive Preamble :v1, 5, 6ms
        Decode HE-SIG-B :v2, 6, 7ms
        Configure Demodulator (Ignore Punctured RUs) :v3, 7, 8ms
        Decode Data Payload :v4, 8, 10ms
    

Derivative 3: Cross-Domain Application

• 3.1 Agricultural IoT (AgTech):

  • Enabling Description: In a large-scale smart farm, a central AP manages a dense network of wireless sensors (soil moisture, temperature, pH) and actuators (irrigation valves, drone controls). The unlicensed spectrum (e.g., 2.4 GHz, 5 GHz) is often crowded with other farm equipment. The AP uses the non-contiguous channel access method to create a robust, low-interference control network. It performs a CCA across an 80 MHz band and identifies narrow, quiet channels. It then transmits a multi-user (MU) PPDU, using the HE-SIG-B to assign each sensor or actuator group to a different, non-contiguous resource unit (e.g., a 26-tone or 52-tone RU). This avoids interference from high-power devices like irrigation pumps or other Wi-Fi networks, ensuring reliable delivery of critical commands and data.
  • Mermaid Diagram:

    graph LR
        subgraph Farm_AP
            A[CCA on 80MHz Band] --> B{Find Quiet RUs};
            B --> C[Generate HE-SIG-B];
            C -- RU Map --> D[Transmit MU-PPDU];
        end
        D --> E[Irrigation Valve 1 \n (RU #1, 26-tone)];
        D --> F[Soil Sensor A \n (RU #5, 26-tone)];
        D --> G[Drone Controller \n (RU #12, 106-tone)];
        H((Interfering Wi-Fi)) -- X -- I(Busy RUs #2,3,4...);
    

• 3.2 In-Hospital Wireless Device Management:

  • Enabling Description: A hospital environment has strict electromagnetic interference (EMI) requirements to protect sensitive medical equipment (e.g., MRI machines, telemetry monitors). A hospital's Wi-Fi network (WH-Fi) uses this method to dynamically "puncture" frequency bands used by critical medical devices. The AP's spectrum management system maintains a real-time database of protected frequencies. Before any transmission, the AP's CCA process is augmented with this database. Any 20 MHz channel overlapping with a protected band is flagged as "busy" even if no RF energy is detected. The AP then transmits a non-contiguous PPDU, using the HE-SIG-A bandwidth field to signal which 20 MHz channels are punctured, ensuring the Wi-Fi signal never occupies the protected bands. This allows for high-throughput Wi-Fi in areas with sensitive equipment.
  • Mermaid Diagram:

    flowchart TD
        subgraph Hospital AP
            A[Start TX Process] --> B{Perform CCA};
            B --> C{Query Medical Device Freq. DB};
            C -- Protected Bands --> D{Create Combined Busy Mask};
            D --> E{Select Idle Channels};
            E --> F[Encode HE-SIG-A/B with Puncturing Info];
            F --> G[Transmit Non-Contiguous PPDU];
        end
        subgraph Patient Room
            H[Patient Monitor (Protected Freq)]
            I[Wi-Fi Tablet]
        end
        G --> I
        style H fill:#f9f,stroke:#333,stroke-width:2px
    

• 3.3 Automotive In-Cabin Wireless:

  • Enabling Description: In a modern vehicle, multiple wireless systems operate in close proximity (e.g., Bluetooth for phone, Wi-Fi for infotainment, dedicated V2X, tire pressure monitoring). This method is used to mitigate intra-vehicle interference. The vehicle's central communication unit acts as an AP. It uses HE-SIG-B resource unit allocation to partition a 40 MHz or 80 MHz channel. Specific RUs are permanently reserved and "nulled" for use by other protocols like Bluetooth AFH (Adaptive Frequency Hopping) or dedicated short-range communications (DSRC). The HE-SIG-B is configured at system startup to signal these RUs as unassigned, effectively creating a static, non-contiguous channel plan within the Wi-Fi frame structure. This prevents the Wi-Fi physical layer from transmitting on frequencies known to be used by other critical in-car systems.
  • Mermaid Diagram:

    pie
        title 80MHz In-Car Spectrum Allocation
        "Infotainment (Wi-Fi)" : 45
        "Bluetooth Coexistence (Punctured)" : 15
        "V2X Sidelink (Punctured)" : 20
        "Unused Guard Band" : 20
    

Derivative 4: Integration with Emerging Tech

• 4.1 AI-driven Predictive Channel Puncturing:

  • Enabling Description: An AI/ML model, running on the AP or a network controller, analyzes historical CCA data and network traffic patterns to predict future channel availability. The model identifies channels that are likely to become busy due to periodic interference (e.g., a neighboring network's beacon, microwave oven operation). Before initiating a TXOP, the AP consults the AI model. The model provides a probabilistic map of channel quality for the next time window. The AP proactively punctures channels with a high probability of future interference, even if they are currently idle according to CCA. This information is then signaled using the HE-SIG-A/B fields. This "predictive puncturing" reduces the likelihood of collisions and retransmissions mid-burst, improving overall network throughput and latency.
  • Mermaid Diagram:

    sequenceDiagram
        participant UserDevice
        participant AP
        participant AI_Engine
        AP->>AI_Engine: Request Channel Prediction for next 100ms
        AI_Engine->>AP: Return P(busy) for channels C1, C2, C3, C4
        AP->>AP: Perform CCA
        alt P(C2 is busy) > 80%
            AP->>AP: Mark C2 as 'punctured'
        else
            AP->>AP: Use CCA result for C2
        end
        AP->>UserDevice: Transmit PPDU with HE-SIG indicating punctured C2
    

• 4.2 IoT Sensor-Informed Dynamic Puncturing:

  • Enabling Description: The wireless network is augmented with a mesh of low-cost, wide-spectrum IoT sensors. These sensors are not part of the primary communication but are dedicated to monitoring RF interference across the entire operational band (e.g., 2.4-6 GHz). They feed real-time spectrum data to the central AP. When a new, non-Wi-Fi interference source is detected by the IoT sensors (e.g., a new radar system, a malfunctioning microwave), the AP immediately updates its channel map and begins puncturing the affected channel in subsequent transmissions, signaling the change via the HE-SIG-A/B fields. This allows the network to adapt to unforeseen or non-standard interference sources much faster than relying solely on the CCA mechanisms of the communicating devices themselves.
  • Mermaid Diagram:

    graph TD
        subgraph IoT_Sensors
            S1[Sensor 1] -->|Spectrum Data| C;
            S2[Sensor 2] -->|Spectrum Data| C;
            S3[Sensor N] -->|Spectrum Data| C;
        end
        subgraph WLAN_System
            C(Central Controller) --> |Interference Map| AP;
            AP -- HE-SIG-A/B --> STA;
        end
        X(Interference Source) -.-> S2;
        Y(Data) -- Transmitted on Punctured Channels --> STA;
    

• 4.3 Blockchain-based Spectrum Access Rights:

  • Enabling Description: In a dynamic spectrum access (DSA) or shared spectrum environment (e.g., CBRS), this method is integrated with a blockchain ledger. The ledger immutably records spectrum usage rights and leases for specific frequency blocks and time slots. Before transmission, an AP queries the blockchain to verify its current rights. It constructs a puncturing mask based not only on CCA results but also on the blockchain record, ensuring it does not transmit in bands currently allocated to other licensed or priority users. The HE-SIG-A/B field containing the non-contiguous channel information effectively serves as a manifest of the spectrum blocks the AP has rights to use for that specific transmission. The hash of this allocation information could be logged on-chain for auditing and compliance verification.
  • Mermaid Diagram:

    sequenceDiagram
        participant AP
        participant Blockchain
        participant STA
    
        AP->>Blockchain: Query Spectrum Rights(Location, Time)
        Blockchain-->>AP: Return Allowed Channels {C1, C3, C4}
        AP->>AP: Perform CCA on {C1, C3, C4}
        note right of AP: CCA finds C3 is busy
        AP->>AP: Final Channel Set = {C1, C4}
        AP->>STA: Transmit HE PPDU (SIG indicates C2,C3 punctured)
        STA->>AP: ACK
        AP->>Blockchain: Log TX(Hash(SIG), Timestamp)
    

Derivative 5: The "Inverse" or Failure Mode

• 5.1 Graceful Degradation Mode:

  • Enabling Description: A wireless terminal, upon detecting critically low battery levels, enters a "graceful degradation" mode. In this mode, instead of transmitting across the widest available non-contiguous bandwidth to maximize throughput, it does the opposite. It performs a CCA and selects only the single best 20 MHz channel (e.g., the one with the lowest noise floor or highest signal strength from the AP's beacon). It then transmits a PPDU with the HE-SIG-A bandwidth field indicating the full potential bandwidth (e.g., 80 MHz) but uses the HE-SIG-B RU allocation to signal that all RUs outside of the selected 20 MHz channel are unassigned. This ensures other devices maintain their NAV timers for the full potential TXOP duration, but the low-power device only needs to power its Power Amplifier (PA) for the narrowest possible band, conserving significant energy.
  • Mermaid Diagram:

    graph TD
        A[Battery Low Event] --> B{Enter Low Power Mode};
        B --> C[Scan 20MHz Channels];
        C --> D{Select Best Channel (e.g., P20)};
        D --> E[Construct 80MHz PPDU];
        E --> F[Set HE-SIG-A BW=80MHz];
        E --> G[Set HE-SIG-B RU Alloc: Puncture S20, S40];
        G & F --> H[Transmit on P20 Only];
    

• 5.2 Interference Beaconing Mode:

  • Enabling Description: A device designed for network diagnostics or lawful interference testing uses this mechanism to signal occupied channels without transmitting a full data payload. The device transmits a very short HE MU PPDU. The HE-SIG-A field indicates a specific bandwidth (e.g., 160 MHz). The HE-SIG-B field's RU Allocation field is then populated with a specific pattern where certain 20 MHz channels are marked as "unassigned" using a null STA ID or a special index. The data portion of the PPDU is either empty or contains minimal diagnostic data. Other devices in the area will decode the preamble, interpret the HE-SIG-B, and treat the "unassigned" channels as busy for the duration specified in the L-SIG, effectively creating a software-defined "keep-out" zone in the spectrum for testing or security purposes.
  • Mermaid Diagram:

    graph TD
        subgraph Diagnostic Tool
            A[Define Keep-Out Channels] --> B(Generate Puncturing Map);
            B --> C(Encode HE-SIG-B);
            C --> D(Transmit Short PPDU w/ Puncturing);
        end
    
        subgraph Network STAs
            E[Receive PPDU] --> F{Decode Preamble};
            F --> G{Read Puncturing Map from HE-SIG-B};
            G --> H["Respect NAV for Punctured Channels"];
        end
    

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Combination Prior Art Scenarios

• Combination 1: Non-Contiguous Channels with MQTT (Message Queuing Telemetry Transport)

  • Description: The non-contiguous channel access method of US 10,687,281 is combined with the open-source MQTT protocol for robust IoT data aggregation in an industrial setting. An AP acts as an MQTT broker. Multiple sensors (subscribers) are sleeping. The AP uses a non-contiguous channel map, signaled via HE-SIG-A/B, to transmit a Wake-up Radio (WuR) packet combined with a Trigger Frame. The trigger frame allocates a unique, small, non-contiguous Resource Unit (RU) to each sensor. Each sensor, upon waking, transmits its small MQTT "PUBLISH" packet (e.g., temperature reading) on its assigned RU. By using non-contiguous RUs, the AP can schedule transmissions in spectral gaps, avoiding interference from heavy machinery. This combines the spectral efficiency of 802.11ax puncturing with the low-overhead, pub/sub architecture of MQTT, creating a highly scalable and resilient industrial IoT network.

• Combination 2: Non-Contiguous Channels with Software-Defined Radio (SDR) and GNU Radio

  • Description: A cognitive radio system is implemented using a generic SDR platform (e.g., a USRP) running the open-source GNU Radio framework. A GNU Radio flow-graph is created to perform real-time, wideband spectrum sensing (CCA). The output of the sensing block is a bitmap of available 20 MHz channels. This bitmap is fed to a custom "HE-SIG-A/B Generator" block. This block, implementing the logic of US 10,687,281, formats the bitmap into a standard-compliant HE-SIG-A bandwidth field and an HE-SIG-B RU allocation field. These fields are then prepended to a data payload, and the entire packet is modulated and transmitted by the SDR. This combination demonstrates that the signaling method is not limited to dedicated ASICs but can be implemented in software, allowing for flexible and experimental use in dynamic spectrum sharing and coexistence research.

• Combination 3: Non-Contiguous Channels with the Robot Operating System (ROS)

  • Description: In a multi-robot autonomous warehouse, a central ROS master node coordinates the actions of a fleet of Automated Guided Vehicles (AGVs). Communication is critical and subject to high levels of RF interference from motors and other systems. The Wi-Fi AP, integrated with the ROS master, uses the non-contiguous channel access method to ensure reliable command-and-control. The AP continuously senses the 5 GHz band. When the ROS master needs to send a high-priority, low-latency command (e.g., "EMERGENCY STOP") to a group of AGVs, the AP identifies all currently available clean mini-channels (even non-contiguous 20MHz segments). It transmits a single HE-MU PPDU addressed to the AGV group, with the HE-SIG-A/B signaling this specific non-contiguous channel map. This ensures the critical ROS message bypasses congested channels, combining the packet-level frequency agility of US 10,687,281 with the distributed systems management of ROS for enhanced industrial automation safety and efficiency.