Securing radio frequency (RF) communication in an RF communications contested area

Abstract

The present disclosure relates to systems, methods, and computer-readable media for securing radio frequency (RF) communication in an RF communications contested area. Systems described herein generate wideband RF noise across a plurality of communication channels within an available RF spectrum for implementing communication channels in the RF communications contested area. Attenuate the wideband RF noise within a selected communication frequency channel in the available RF spectrum. Synchronize the selected communication frequency channel with a transceiver. Transmit a communication in the selected communication frequency channel.

Description

SECURING RADIO FREQUENCY (RE) COMMUNICATION IN AN RF COMMUNICATIONS CONTESTED AREABACKGROUND

[0001] The current approach for deploying unmanned systems and payloads leaves the associated radio frequency (RF) communication systems vulnerable to adversarial systems and techniques and enemy communication countermeasures leading to an RF communications contested region. Adversarial RF communication countermeasures and communications within an RF communications contested area include but are not limited to: jamming of the RF signals used to communicate between a command center, the Warfighter, and unmanned systems and payloads; interception of sensitive communications between a command center, the Warfighter, and unmanned systems and payloads; and operation of adversarial communication networks within a battlefield. These networks may support communications among enemy personnel, sensors, unmanned aerial vehicles (UAVs), missiles, and other deployed assets.BRIEF DESCRIPTION OF THE DRAWINGS

[0002] FIG. 1 illustrates a high-level system diagram depicting a Smoke and Windows Virtual Private RF Communications Network, according to at least one embodiment of the present disclosure.

[0003] FIG. 2 is a representation of a schematic system architecture diagram for a Wideband Noise Generation / Configurable Notch Filter, according to at least one embodiment of the present disclosure.

[0004] FIG. 3 is a representation of a schematic system architecture diagram for the Smoke and Windows Virtual Private RF Communications Network, according to at least one embodiment of the present disclosure.

[0005] FIG. 4 illustrates a block diagram of an RF communication architecture including an RF Communication System, an RF Communication Controller, and a Receptive Transceiver, according to at least one embodiment of the present disclosure.

[0006] FIG. 5 is a representation of a Wideband Noise Generator and Configurable Notch Filter Device creating a communication window for a friendly transceiver while disrupting enemy transceivers, according to at least one embodiment of the present disclosure.- 1 - 48623-00251-PCT

[0007] FIG. 6 illustrates an example series of acts for securing RF communications in an RF communications contested area, according to at least one embodiment of the present disclosure.DETAILED DESCRIPTION

[0008] The present disclosure generally relates to radio frequency (RF) communication, particularly RF communication in a communications contested zone (e.g., in an area having adversarial communications behavior). Adversarial communication behavior may include communications that have been disrupted due to actions by an adversary and / or communications that have been disrupted due to actions by a friendly source. In some situations, communications that have been disrupted due to friendly actions may still disrupt friendly communications.

[0009] The Smoke and Windows Virtual Private RF Communications Network addresses adversarial communications behaviors. The techniques of the present disclosure will allow warfighters the ability to securely employ unmanned platforms in various mission profiles within a virtually private network. The present disclosure uses a two-prong strategy: it denies all RF communications within targeted frequencies ("Smoke"), and opens secure, private RF channels ("Windows"). The system denies all RF communications by overwhelming the RF spectrum with controlled noise (“Smoke”) that disables enemy communications, and creates narrow, secure channels (“Windows”) that only friendly forces can use.

[0010] As an illustrative example, systems (and / or methods and computer readable media) described herein generate wideband RF noise across a plurality of communication channels within an available RF spectrum for implementing communication channels in the RF communications contested area. The systems described herein attenuate the wideband RF noise within a selected communication frequency channel in the available RF spectrum. The systems may further synchronize the selected communication frequency channel with a transceiver. The systems may transmit a communication in the selected communication frequency channel.

[0011] The present disclosure provides a number of practical applications that provide benefits and / or solve problems associated with communicating in RF communications contested areas. By way of example and not limitation, some of these benefits will be discussed in further detail below.- 2 - 48623-00251-PCT

[0012] For example, as will be discussed herein, a smoke and windows (SAW) virtual private RF communications network prevents other parties (or adversaries) from communicating within the RF communications contested area. The minimum power level required for successful RF communication between two devices is often constrained by the ambient noise level (from both human-caused and natural sources) present at each device’s receiver. For example, a 30dB increase (lOOOx power increase) in ambient power noise present at both devices may require a lOOOx increase in the transmission power required to successfully communicate. By overwhelming all frequency channels except the narrow windows (or notches), other parties that plan to use those frequency channels will have to exert an impractical amount of energy to communicate on those channels, making such communication effectively infeasible without knowing which channels are clear of the added power. Meanwhile, friendly transceivers are synchronized to operate within the attenuated windows, enabling secure and reliable communication without requiring additional transmission power or new waveforms.

[0013] As will be discussed below, the smoke and windows (SAW) virtual private RF communications network broadcasts wideband noise over the entire RF spectrum to prevent interception. Enemy receivers often scan tens of thousands of narrow bandwidth channels to identify those with RF power levels above background noise as potential communication links. The SAW technology obscures friendly channels by elevating RF noise power levels in all unused channels to levels comparable to those in active channels, preventing adversaries from easily determining which channels are in use. Because the RF spectrum can include tens of thousands of narrow channels, the obfuscation of these channels prevents an adversary from making a simple determination of which RF communication channels are being used by friendly forces.

[0014] Similarly, the smoke and windows (SAW) virtual private RF communications network enhances sensor effectiveness by enabling secure long- range communication between sensors and command systems, even in RF-contested environments. Rather than extending sensor detection range, the SAW system ensures that data from sensors can be transmitted reliably over secure channels without being jammed or intercepted. By flooding the RF spectrum with wideband noise and creating narrow communication windows for friendly devices, the system neutralizes adversarial jamming and prevents disruption of sensor data links.- 3 - 48623-00251-PCT

[0015] As illustrated in the foregoing discussion, the present disclosure utilizes a variety of terms to describe features and advantages of one or more implementations of a network isolation management system described herein. Additional detail will now be provided regarding the meaning of some of these terms.

[0016] As will be discussed herein, the SAW communications network generates wideband RF noise across a plurality of communication channels. As used herein, wideband RF noise refers to radio frequency energy distributed across a large portion of the RF spectrum to increase the noise floor and disrupt communications. In one or more embodiments, wideband RF noise refers to a signal that spans multiple communication channels within an RF spectrum. By way of example and not limitation, wideband RF noise may refer to one or more of white Gaussian noise or pseudorandom noise waveforms. In one or more embodiments, the wideband noise generator and configurable notch filter device is implemented using a highspeed digital signal processing platform capable of direct RF waveform synthesis. In such embodiments, a radio-frequency system-on-chip (RFSoC) or similar integrated RF processing device directly synthesizes a wideband noise waveform (e.g., white Gaussian noise or pseudorandom noise).

[0017] In one or more embodiments, the digital signal processing resources and high-speed digital-to-analog converters of the RFSoC enable direct synthesis of a wideband RF noise signal with one or more spectral notches or windows incorporated into the synthesized waveform. In such embodiments, the location, bandwidth, and depth of the notches may be digitally controlled, allowing dynamic creation and movement of communication windows without requiring separate analog filtering stages.

[0018] By way of example and not limitation, an RFSoC platform may be used to generate the wideband noise signal and implement the configurable notch functionality entirely in the digital domain prior to RF amplification and radiation. It is to be noted, the disclosed techniques are not limited to any particular hardware platform and may be implemented using other digital, mixed-signal, or hybrid architectures.

[0019] As will be discussed in further detail below, the SAW communications network attenuates the wideband RF noise within a selected communication frequency channel in the available RF spectrum. As used herein, attenuating refers- 4 - 48623-00251-PCTto the process of reducing the strength or power of a signal or noise within a specified frequency range. In one or more embodiments, attenuating refers to reducing the power level of wideband RF noise within a selected communication frequency channel to create a communication window. In one or more embodiments, attenuating refers to applying a notch filter or similar filtering technique to decrease the RF noise power level in the selected channel by a defined amount. By way of example and not limitation, the RF noise power level may be decreased about 30 decibels relative to adjacent channels.

[0020] As will be discussed herein, a transceiver is used to send and receive communication. As used herein, a transceiver refers to a device that can transmit and / or receive communications. In one or more embodiments, a transceiver refers to a frequency-agile device capable of transmitting and / or receiving signals across multiple channels. In one or more embodiments, a transceiver refers to a device configured to dynamically synchronize with a communication window created by attenuating wideband RF noise.

[0021] Additional details regarding example implementations of the smoke and windows virtual private RF communications network will now be discussed in connection with one or more example implementations shown in the figures. For example, FIG. 1 illustrates a high-level system diagram depicting a Smoke and Windows Virtual Private RF Communications Network (the “network”) in accordance with one or more embodiments. The Smoke and Windows Virtual Private RF Communications Network generates a Virtual Private RF Communications Network in an RF communications contested area 102. An RF communications contested area 102 is any area that includes one or more parties that use signals to communicate that another party may interfere with.

[0022] The command center 104 may be a centralized location or facility that sends information to at least one channel and notch filter selection coordination device 106. By way of example and not limitation, the information sent may be one or more of instructions for the channel and notch filter selection coordination device 106 to follow, communications to pass through the channel and notch filter selection coordination device 106, or status updates. In one or more embodiments, the channel and notch filter selection coordination device 106 may send information to the command center 104. By way of example and not limitation, the information may- 5 - 48623-00251-PCTinclude one or more of confirmation of receipt of information, error messages, information requests, or periodic updates on system resources.

[0023] The channel and notch filter selection coordination device 106 coordinates with the command center 104, at least one friendly transceiver s) 108, and the wideband noise generator and configurable notch filter device(s) 112. In one or more embodiments, the channel and notch filter selection coordination device 106 selects one or more frequency channels to have a window. In one or more embodiments, the channel and notch filter selection coordination device 106 synchronizes the selected communication frequency channel with a transceiver. In one or more embodiments, the transceiver is a frequency-agile transceiver. In one or more embodiments, the channel and notch filter selection coordination device 106 is centrally coordinated. In one or more embodiments, the channel and notch filter selection coordination device 106 is semi-centrally coordinated.

[0024] In one or more embodiments, the channel and notch filter selection coordination device 106 determines and facilitates the wideband RF noise generation settings, and the frequency channels of the notches. In one or more embodiments, the channel and notch filter selection coordination device 106 in conjunction with the command center, manages channel selection for at least one sensor deployed in the RF communications contested area 102. In one or more embodiments, the channel and notch filter selection coordination device 106 controls notch filter selection of the one or more wideband noise generator and configurable notch filter device(s) 112 that are deployed in the RF communications contested area 102. In one or more embodiments, the notch filter s are configured to frequency bands corresponding to the communication channels selected by the wideband noise generator and configurable notch filter device(s) 112. The channel and notch filter selection coordination device 106 communicates with at least one wideband noise generator and configurable notch filter device(s) 112.

[0025] By way of example and not limitation, the channel and notch filter selection coordination device 106 may determine which RF sub-bands are designated as windows and when those designations change via one or more of an algorithm, a pattern, an event, and external influences. In one or more embodiments, an algorithm used to help determine window designation and changes may include one or more of deterministic sequences, pseudo-random sequences, or hybrid approaches. In one or more embodiments, a pattern contributes to designation of the- 6 - 48623-00251-PCTwindows and / or window changes by cycling through predefined frequency sets or bands.

[0026] In one or more embodiments, the window designations and changes are at least partially event driven. By way of example and not limitation, windows may be created or moved in response to one or more of detected enemy activity, interference, or phase of the mission. In one or more embodiments, external influences (e.g., operator input, mission planning data, or sensor feedback) may contribute to window designation and changes. In one or more embodiments, the channel and notch filter selection coordination device 106 does not expose or broadcast the selection logic itself; rather, it ensures that friendly devices and the notch-filter system remain synchronized in their understanding of which channels are windows at a given time.

[0027] The selection of window channels may be architecture-agnostic and may be implemented in multiple ways depending on mission requirements. In one or more embodiments, the channel and notch filter selection coordination device 106 may select window channels via pseudo-random or cryptographically seeded selection, where window locations appear random to an adversary but are predictable to friendly forces with shared context. In one or more embodiments, the channel and notch filter selection coordination device 106 may select window channels via predefined hopping tables or codebooks, loaded prior to deployment.

[0028] In one or more embodiments, the channel and notch filter selection coordination device 106 may select window channels via adaptive selection, where channels are chosen based on measured interference, spectral occupancy, or adversary behavior. In one or more embodiments, the channel and notch filter selection coordination device 106 may select window channels via hybrid approaches, combining deterministic structures with randomization. In one or more embodiments, the channel and notch filter selection coordination device 106 does not depend on frequency hopping of the radios themselves. This allows existing frequency-agile radios to continue operating normally; the SAW system instead manipulates the ambient RF noise environment to define usable channels. This distinction allows the invention to work with existing radios and protocols without waveform modification.

[0029] In one or more embodiments, the coordination information may not be continuously broadcast in-band within the contested RF spectrum. In one or more- 7 - 48623-00251-PCTembodiments, pre-shared coordination context, such as time-indexed schedules, hopping tables, or seed material loaded before deployment is how the coordination information is communicated. In one or more embodiments, out-of-band or low- duty-cycle signaling is how the coordination information is obtained by the friendly transceiver(s) 108. In one or more embodiments, the cycle signaling uses existing secure channels. In one or more embodiments, coordination between friendly devices is facilitated via implicit synchronization, where friendly devices independently compute window locations using shared parameters (e.g., time, mission phase, or internal state). In one or more embodiments, friendly devices do not receive explicit frequency instructions in real time, they arrive at the same window selection independently of the channel and notch filter selection coordination device 106. This reduces interception risk and command-and-control burden, allowing operations even when real-time coordination links are degraded or denied.

[0030] The wideband noise generator and configurable notch filter device(s) 112 is the noise source of the wideband noise. In one or more embodiments, the wideband noise generator and configurable notch filter device(s) 112 generates wideband RF noise across a plurality of communication channels within an available RF spectrum for implementing communication channels in the RF communications contested area 102. In one or more embodiments, the wideband noise generator and configurable notch filter device(s) 112 attenuates the wideband RF noise within a selected communication frequency channel in the available RF spectrum. In one or more embodiments, the wideband noise generator and configurable notch filter device(s) 112 uses a notch filter to attenuate the wideband RF noise.

[0031] In one or more embodiments, the wideband noise generator and configurable notch filter device(s) 112 is configured such that the center frequency of the narrow bandwidth notch filters corresponding to the one or more selected RF communication channels to be attenuated can be dynamically configured. In one or more embodiments, attenuating the wideband RF noise within the selected communication frequency channel comprises attenuating the wideband RF noise according to a dynamically adjustable center frequency and bandwidth for the selected communication frequency channel. In one or more embodiments, the dynamically adjustable center frequency is adjusted to correspond to a frequencyhopping pattern of the transceiver. In one or more embodiments, the wideband noise- 8 - 48623-00251-PCTgenerator and configurable notch filter device(s) 112 allows denial of enemy RF communications in the RF communications contested area while simultaneously allowing the RF communications of friendly forces. More detail on the wideband noise generator and configurable notch filter device(s) 112 will be discussed in connection with FIG. 2.

[0032] In one or more embodiments, the RF noise level is mission-dependent and adaptive, not fixed. By way of example and not limitation, the determination of the RF noise level is based on one or more of expected enemy receiver sensitivity, expected enemy receiver link budgets, desired denial margin (i.e., how much additional transmit power an adversary would need to overcome the noise), geographic and propagation considerations (e.g., terrain and antenna placement), and friendly system self-protection (i.e., ensuring windows maintain sufficient signal-to- noise ratio). In one or more embodiments, the wideband noise generator and configurable notch filter device(s) 112 generates the wideband RF noise by increasing a power level of the wideband RF noise to at least the level of adversarial jamming signals. The goal is not simply to overpower enemy jamming, but to raise the effective noise floor such that adversarial communications become impractical while friendly communications remain viable within coordinated windows. In a battlefield environment (as opposed to an urban noise-rich environment), this controlled elevation of the noise floor is especially impactful because baseline ambient RF noise is relatively low and predictable.

[0033] As shown in FIG. 1, one or more friendly transceiver(s) 108 communicates with the channel and notch filter selection coordination device 106. In one or more embodiments, the friendly transceiver(s) 108 receives information from the channel and notch filter selection coordination device 106 about the channel(s) selected to be windows. In one or more embodiments, the channel and notch filter selection coordination device 106 receives information from the friendly transceiver that includes information about the channel(s) the friendly receiver is using to communicate (e.g., a list of channels, a channel frequency-hopping algorithm, a frequency-hopping pattern) and the channel and notch filter selection coordination device 106 creates a window on that channel(s). In one or more embodiments, both the channel and notch filter selection coordination device 106 and the friendly receive information from the command center 104 that includes- 9 - 48623-00251-PCTinformation about which channel(s) to have windows in and which channel(s) to use respectively.

[0034] In one or more embodiments, the command center 104 transmits a communication to the friendly transceiver(s) 108 in the selected communication frequency channel that has a window. In one or more embodiments, transmitting the communication includes selecting a first communication frequency channel of a plurality of communication frequency channels for the communication and transmitting the communication includes transmitting the communication on the first communication frequency channel. In one or more embodiments, a first communication is transmitted, and the system selects a second communication frequency channel of the plurality of communication frequency channels and transmits a second communication on the second communication frequency channel.

[0035] In one or more embodiments the friendly transceiver(s) 108 includes a receiver configured to receive a communication along a communication frequency channel. In one or more embodiments the friendly transceiver(s) 108 includes a receiver controller. In one or more embodiments the receiver controller is configured to adjust the receiver to operate on a selected communication frequency channel corresponding to an attenuated wideband RF noise and synchronize the receiver with a frequency-hopping pattern. In one or more embodiments, the receiver controller is configured to dynamically adjust a center frequency and bandwidth of the selected communication frequency channel. In one or more embodiments, the friendly transceiver(s) 108 is a frequency-agile transceiver. In one or more embodiment the friendly transceiver(s) 108 includes a frequency agile receiver at a receiving device configured to receive the communication while the wideband RF noise generator generates wideband RF noise.

[0036] As further shown in FIG. 1, there may be an enemy transceiver(s) 110 in the RF communications contested area 102. The enemy transceiver(s) 110 may be any transceiver controlled by another party.

[0037] FIG. 2 is a representation of a schematic system architecture diagram for a wideband noise generator and configurable notch filter device (s) 112, according to at least one embodiment of the present disclosure. In one or more embodiments, the wideband noise generator and configurable notch filter device(s) 112 includes one or more of: a wideband noise module 202, a power supply module 204, a wideband power amplifier 206, a channel filter(s) 208, an RF coupler 210, a spectrum analyzer- 10 - 48623-00251-PCT212, an antenna matching network 214, and a wideband antenna 216. The wideband noise generator and configurable notch filter device(s) 112 takes a noise signal, boosts it by a certain amount of power, suppresses noise in a narrow slice of frequencies to create a window, verifies performance with a spectrum analyzer 212, matches the signal to the antenna, and sends the communication.

[0038] The power supply module 204 provides the required voltages and current to the wideband noise module 202 and the wideband power amplifier 206. The power supply module 204 is any unit that provides power (e.g., electrical) to the wideband noise module 202 or the wideband power amplifier 206. By way of example and not limitation, the power supply module may include a power supply that contains a 24-volt direct current output capable of delivering up to 10 amps of power. In one or more embodiments, the power supply module 204 may take an input voltage of 24 volts DC and converts it to a stable output of 15 VDC with the capacity to supply 250 milliamperes.

[0039] As shown in FIG. 2, the wideband noise generator and configurable notch filter device(s) 112 includes a wideband noise module 202. In one or more embodiments, the wideband noise module 202 generates a broadband noise signal across a plurality of communication channels within an RF spectrum available for implementing communication channels in the RF communications contested area 102. In one or more embodiments, the wideband RF noise comprises pseudorandom noise waveforms. In one or more embodiments, the wideband RF noise comprises white Gaussian noise. In one or more embodiments, the wideband noise module 202 receives power (e.g., 15 volts at 160 milliamperes) from the power supply module 204. In one or more embodiments, the wideband noise module 202 communicates with a wideband power amplifier 206 which boosts the noise signal power to the level needed for effective radiation over the available channels in the RF communications contested area 102.

[0040] As further shown in FIG. 2, the wideband noise generator and configurable notch filter device(s) 112 includes a channel filter(s) 208. The channel filter(s) 208 creates the notch or window. In one or more embodiments, the channel filter(s) 208 is configured to selectively attenuate the RF noise within a selected communication frequency channel to create a communication window. In one or more embodiments, the channel filter(s) 208 communicates with a controller configured to select a communication channel to attenuate the wideband RF noise- 11 - 48623-00251-PCTwithin and facilitate adjustment of the transceiver to the selected communication frequency channel. In one or more embodiments, the controller includes a communication frequency channel selector configured to select the one of the plurality of communication frequency channels.

[0041] In one or more embodiments, the channel filter(s) 208 is a notch filter. In one or more embodiments, the channel filter(s) 208 is tuned mechanically (e.g., by adjusting a variable capacitor or inductor, rotating a tuning screw or plunger within a resonant cavity, sliding a dielectric element to alter effective permittivity, or physically stretching or compressing a transmission line section to change its electrical length). In one or more embodiments, the channel filter(s) 208 is tuned manually. In one or more embodiments, the channel filter(s) 208 is tuned electrically. In one or more embodiments, the channel filter(s) 208 is tuned via digital assistance.

[0042] In one or more embodiments, the channel filter(s) 208 selectively suppresses the RF noise over one or more narrow sub-bands. In one or more embodiments, the channel filter(s) 208 suppresses the internally generated noise signal prior to radiation. In one or more embodiments, the channel filter(s) 208 is adjustable in one or more of the center frequency bandwidth, depth, and timing. This enables a dynamic window creation. From the receiver’s perspective, windows appear as anomalous regions of reduced noise, but because surrounding channels are also noisy, adversaries cannot trivially distinguish friendly communications from background RF activity.

[0043] In one or more embodiments, the channel filter(s) 208 attenuates the RF noise within the selected channel by sending instructions to the wideband noise module 202 to not boost the power for the selected channel. In one or more embodiments the channel filter(s) 208 attenuates the RF noise within the selected channel by reducing the power on that channel. In one or more embodiments, the channel filter(s) 208 attenuates the RF noise within the selected channel by employing tiny microphones to capture ambient sounds, and generating an opposite sound wave (e.g., 180° out of phase) that cancels out the original noise. In one or more embodiments, attenuating the wideband RF noise within the selected communication frequency channel comprises a bandwidth of less than 1 megahertz.

[0044] In one or more embodiments, the wideband noise generator and configurable notch filter device(s) 112 includes an RF coupler 210. The RF coupler 210 samples a portion of the radio frequency signal on the transmission path so- 12 - 48623-00251-PCTproperties of the sound wave can be monitored without disrupting the main signal. By way of example and not limitation, an RF coupler 210 may include one or more of a 20 dB directional coupler used to feed a spectrum analyzer, a bidirectional coupler used for forward and reflected power measurements in an antenna tuning network, and a multisection microstrip coupler integrated on a printed circuit board for wideband noise monitoring.

[0045] As shown in FIG. 2, the wideband noise generator and configurable notch filter device(s) 112 includes a spectrum analyzer 212. The spectrum analyzer 212 measures the frequency-domain representation of an RF signal. In one or more embodiments, the spectrum analyzer 212 displays the frequency-domain representation of an RF signal, showing its power distribution across a range of frequencies. In one or more embodiments, the spectrum analyzer 212 is an electronic test instrument that converts an input signal into a visual plot of amplitude versus frequency, enabling analysis of signal characteristics such as bandwidth, harmonics, and spurious emissions.

[0046] In one or more embodiments, the wideband noise generator and configurable notch filter device(s) 112 includes an antenna matching network 214. The antenna matching network 214 optimizes the impedance between the transmitter and the antenna to maximize power transfer and minimize signal reflections. In one or more embodiments, the antenna matching network 214 is a circuit composed of reactive components (e.g., inductors, capacitors, or transmission line sections) designed to transform the impedance of an antenna to match the source or load impedance, typically 50 ohms in RF systems.

[0047] In one or more embodiments, the wideband noise generator and configurable notch filter device(s) 112 includes a wideband antenna 216. The wideband antenna 216 radiates or receives RF signals across a broad frequency range, enabling communication or signal transmission over multiple channels without requiring multiple antennas. In one or more embodiments, the wideband antenna 216 is an antenna designed to operate over a large bandwidth, typically spanning several octaves or decades of frequency, while maintaining acceptable impedance matching and radiation characteristics. By way of example and not limitation a wideband antenna 216 may include one or more of a log-periodic dipole arrays for broadband RF testing, discone antennas used for VHF / UHF monitoring, and spiral antennas employed in electronic warfare systems for wideband signal- 13 - 48623-00251-PCTcoverage. In one or more embodiments, the RF power transmitted by the wideband antenna 216 will exceed 4W.

[0048] FIG. 3 is a representation of a schematic system architecture diagram for the Smoke and Windows Virtual Private RF Communications Network, according to at least one embodiment of the present disclosure. As shown in FIG. 3, the Smoke and Windows Virtual Private RF Communications Network secures radio frequency (RF) communication in RF communications contested area 302. In one or more embodiments, the RF communications contested area 302 includes a command center 306.

[0049] As discussed above, the command center 306 may be a centralized location or facility that sends information to at least one channel and notch filter selection coordination device 308. The channel and notch filter selection coordination device 308 coordinates with the wideband noise generator and configurable notch filter device(s) 312 to attenuate the wideband RF noise within one or more selected communication frequency channels and the selected channel is synchronized with a transceiver. In one or more embodiments, synchronizing the selected communication frequency channel with the transceiver is performed via a controller. In one or more embodiments, the controller is a computer. In one or more embodiments, the selected communication frequency channel includes a plurality of communication frequency channels, and wherein attenuating the wideband RF noise includes attenuating the wideband RF noise across the plurality of communication frequency channels. In one or more embodiments, a transceiver is configured to transmit a communication along the selected communication frequency channel while the wideband noise generator and configurable notch filter device(s) 312 generates the RF noise.

[0050] In accordance with at least one embodiment of the present disclosure, the techniques of the present disclosure may result in the wideband noise generator and configurable notch filter device(s) 312 generating wideband white gaussian noise over the 100MHz-200MHz bandwidth with an RF power output of greater than 8W. The wideband noise generator and configurable notch filter device(s) 312 may configure its notch filter to provide >30dB attenuation of the wideband noise signal over a <lMHz bandwidth at any center frequency between 100MHz and 200MHz. The RF power transmitted by the wideband noise generator and configurable notch filter device(s) 312 through its wideband antenna / s may exceed 4W. The Smoke and- 14 - 48623-00251-PCTWindows Virtual Private RF Communications Network may demonstrate the ability of the wideband noise generator and configurable notch filter device(s) 312 to incur a >20dB increase in transmitted power required for successful communication to occur between two RF transceiver enabled enemy devices. The Smoke and Windows Virtual Private RF Communications Network may demonstrate the ability to obscure communications of two friendly RF transceivers utilizing a selected channel corresponding to the notch filter bandwidth configured in the wideband noise generator and configurable notch filter device(s) 312 from enemy communications systems by raising the noise floor of adjacent channels located in the 100MH - 200MHz frequency span.

[0051] In one or more embodiments, the command center 306 communicates with sensor(s) 310 on the one or more attenuated frequency channels. The sensor(s) 310 are data sources for the command center 306 that collect information about the environment. In one or more embodiments, the sensor(s) 310 are electronic devices integrated into unmanned platforms or deployed in the field to collect mission- critical data and transmit this data securely to a command center through protected RF channels. In one or more embodiments, sensors function as data acquisition nodes that interface with the channel and notch filter selection coordination device 308 to ensure their transmissions occur through dynamically configured notch- filtered windows. By way of example and not limitation, a sensor(s) 310 may include one or more of electromagnetic signals, environmental sensors, chemical sensors, biological sensors, radiological sensors, imaging sensors (e.g., optical camera, infrared camera), acoustic sensors (e.g., microphones, sonar), motion sensors, or target information. This design allows sensors to maintain uninterrupted, secure communication even when the surrounding RF spectrum is flooded with wideband noise to deny enemy communications.

[0052] As shown in FIG. 3 an inside enemy transceiver s) 304 may be within the RF communications contested area 302. The inside enemy transceiver(s) 304 may try to communicate with an outside enemy transceiver(s) 314 that is positioned outside the RF communications contested area 302. The communication between the inside enemy transceiver(s) 304 and the outside enemy transceiver(s) 314 may be disrupted because of the wideband RF noise that is generated in all, but the selected communication frequency channel(s).- 15 - 48623-00251-PCT

[0053] As a specific non-limiting example, consider an RF communications contested area 302 that is a 5km by 20km rectangle. Along the “back” 5km edge of the area is located a command center 306. Six sensors 310 equipped with frequency agile transceivers are deployed along the 5km front edge of the area at a 20km distance from the command center 306. Six additional sensors 310 are deployed in the region between the command center 306 and the 5km front edge. The command center 306 supports frequency agile RF communication between its communication devices and other communication devices. The 100kmA2 area encompassing the twelve sensors 310 and including the command center 306 is RF communications contested.

[0054] Eight wideband noise generator and configurable notch filter device(s) 312, each supporting one or more configurable notch filter s, may be deployed in the RF communications contested area 302. These eight wideband noise generator and configurable notch filter device(s) 312 may be distributed throughout the RF communications contested area 302.

[0055] At least one channel and notch filter selection coordination device 308 may be deployed in the RF communications contested area 302. The channel and notch filter selection coordination device 308, in conjunction with the command center 306, manages channel selection for the twelve sensors 310 deployed in the RF communications contested area 302. The channel and notch filter selection coordination device 308 may also control notch filter selection of the eight wideband noise generator and configurable notch filter device(s) 312 that are deployed in the RF communications contested area 302. The notch filters may be configured to frequency bands corresponding to the communication channels selected by the channel and notch filter selection coordination device 308. Communication with the sensors 310 and other friendly elements may be transmitted along the specific frequency bands from the notch filter s based on the frequency selection scheme determined by the channel and notch filter selection coordination device 308.

[0056] FIG. 4 illustrates a block diagram of an RF communication architecture including an RF communication system 402, an RF communication controller 410, and a Field transceiver(s) 418, according to at least one embodiment of the present disclosure. An RF communication system 402 includes a wideband noise generator(s) 404, an attenuator 406, and a transceiver 408. A wideband noise generator(s) 404 is an electronic device that produces electrical signals across a- 16 - 48623-00251-PCTbroad frequency range. In one or more embodiments, a wideband noise generator(s) 404 floods the RF spectrum with high-power noise (“smoke”) while leaving dynamically configured notch-filtered windows for friendly communication. By way of example and not limitation the noise may be generated over a 100MHz-200MHz bandwidth with an RF power output of greater than 8W.

[0057] In one or more embodiments, the RF communication system 402 includes an attenuator 406. An attenuator 406 is an electronic component or device that reduces the amplitude or power of a signal without significantly distorting its waveform. In one or more embodiments, the RF communication system 402 includes a transceiver 408. In one or more embodiments, the transceiver 408 receives signals from the RF communication controller 410 that include instructions, or information related to generating noise, and / or attenuating the selected channels. By way of example and not limitation, the information may include one or more of what power level the wideband noise generator(s) 404 should reach, the frequency channels to be attenuated, and instructions to be sent to the field transceiver(s) 418 to synchronize to an attenuated frequency channel. In one or more embodiments, the transceiver 408 sends information to the RF communication controller 410 and / or the field transceiver(s) 418.

[0058] As shown in FIG. 4, the RF communication controller 410 communicates with the RF communication system 402 and / or the field transceiver s) 418. The RF communication controller 410 includes a frequency selection manager 412, a wideband noise generation manager 414, and a synchronization engine 416. A frequency selection manager 412 selects the frequency channel(s) to be attenuated. In one or more embodiments, the frequency selection manager 412 may receive instructions from a user to determine which channel(s) to select. In one or more embodiments, the channel(s) are selected based on an algorithm.

[0059] The frequency selection manager 412 may communicate with the synchronization engine 416 to determine which channel(s) to select to be attenuated. The synchronization engine 416 may coordinate with the receptive transceiver to facilitate frequency-hopping for the attenuated channel. In one or more embodiments, the synchronization engine 416 obtains rules to coordinate the attenuator 406 attenuating the correct channel and the field transceiver(s) 418 being on that channel, (e.g., the selected channel changes every 5 milliseconds, the selected channel changes every time a single packet is transmitted).- 17 - 48623-00251-PCT

[0060] As shown in FIG. 4, the RF communication controller 410 includes a wideband noise generation manager 414. The wideband noise generation manager 414 obtains information to facilitate wideband noise generation. By way of example and not limitation, the information may include one or more of the frequency range over which to generate the noise, the power level to use, and the noise type (e.g., white Gaussian noise, pseudorandom noise. By way of example and not limitation, this information may be obtained in one or more of the following ways system specifications, user input, and sensors (e.g. RF spectrum analyzer, RF monitoring sensor). In one or more embodiments, the wideband noise generation manager 414 uses the information obtained to generate instructions to send to RF communication system 402 for use by the wideband noise generator(s) 404 to generate the wideband RF noise.

[0061] As further shown in FIG. 4, a field transceiver s) 418 may receive information from the RF communication controller 410 to facilitate secure communication. In one or more embodiments, the field transceiver(s) 418 may be a part of a larger device(s) (e.g., radio, sensor). The field transceiver(s) 418 includes a frequency channel controller 422. A frequency channel controller 422 communicates with the RF communication controller 410 to determine the selected frequency channel. The frequency channel controller 422 tunes the field transceiver(s) 418 to the selected frequency channel, allowing the field transceiver s) 418 to communicate on the attenuated channel.

[0062] Additional detail will now be discussed in connection with example workflows showing implementations of the SAW communication network in accordance with one or more implementations. In particular, FIG. 5 is a representation of a Wideband Noise Generator and Configurable Notch Filter Device creating a communication window for a friendly transceiver while disrupting enemy transceivers, according to at least one embodiment of the present disclosure. In this example, the RF communications contested area 102 has available RF channels 502. The available RF channels 502 contain a plurality of RF channels (e.g., tens of thousands of discrete narrow bandwidth channels) including a first channel 504, a second channel 506, and a third channel 508. As shown in FIG. 5 each channel has a noise floor that is approximately similar. The area may become an RF communications contested area, and friendly transceivers and enemy transceivers may tune into one or more of the available channels.- 18 - 48623-00251-PCT

[0063] As shown in FIG. 5, the SAW communication network 516 may secure RF communications in the area for the friendly forces. The SAW communication network 516 generates wideband noise across the majority of the available RF channels 502 raising the noise floor across the RF spectrum. In this example the enemy transceiver(s) 110 are tuned into the first channel 510 and the wideband noise prevents the enemy transceiver(s) from being able to communicate without a much higher minimum power level. In this example, the SAW communication network 516 creates a narrow channel (e.g., 12.5 kilohertz) on the second channel 512, and attenuates the wideband RF noise on that channel. The friendly transceiver(s) 108 tune into the second channel 512 and is able to communicate.

[0064] Turning now to FIG. 6, this figure illustrates an example series of acts for securing radio frequency (RF) communication in an RF communications contested area. While FIG. 6 illustrates acts according to one or more implementations, alternative implementations may omit, add to, reorder, and / or modify any of the acts shown in FIG. 6. The acts of FIG. 6 may be performed as part of a method. Alternatively, a system can perform the acts of FIG. 6.

[0065] As shown in FIG. 6, the series of acts 600 includes an act 610 of generating wideband RF noise across a plurality of communication channels within an available RF spectrum for implementing communication channels in the RF communications contested area.

[0066] As further shown in FIG. 6, the series of acts 600 includes an act 620 of attenuating the wideband RF noise within a selected communication frequency channel in the available RF spectrum.

[0067] As further shown in FIG. 6, the series of acts 600 includes an act 630 of synchronizing the selected communication frequency channel with a transceiver.

[0068] As further shown in FIG. 6, the series of acts 600 includes an act 650 of transmitting a communication in the selected communication frequency channel.

[0069] In one or more embodiments, attenuating the wideband RF noise within the selected communication frequency channel comprises attenuating the wideband RF noise according to a dynamically adjustable center frequency and bandwidth for the selected communication frequency channel. In one or more embodiments, the dynamically adjustable center frequency is adjusted to correspond to a frequencyhopping pattern of the transceiver. In one or more embodiments, the wideband RF noise comprises pseudorandom noise waveforms. In one or more embodiments, the- 19 - 48623-00251-PCTwideband RF noise comprises white gaussian noise. In one or more embodiments, synchronizing the selected communication frequency channel with the transceiver is performed via a controller.

[0070] In one or more embodiments, the selected communication frequency channel includes a plurality of communication frequency channels, and wherein attenuating the wideband RF noise includes attenuating the wideband RF noise across the plurality of communication frequency channels. In one or more embodiments, transmitting the communication includes selecting a first communication frequency channel of the plurality of communication frequency channels for the communication and transmitting the communication includes transmitting the communication on the first communication frequency channel. In one or more embodiments, the communication is a first communication, and further comprising selecting a second communication frequency channel of the plurality of communication frequency channels, and transmitting a second communication on the second communication frequency channel.

[0071] In one or more embodiments, generating the wideband RF noise comprises increasing a power level of the wideband RF noise to at least the level of adversarial jamming signals. In one or more embodiments, attenuating the wideband RF noise within the selected communication frequency channel comprises a bandwidth of less than 1 megahertz.

[0072] The steps and / or actions of the methods described herein may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper operation of the method that is being described, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0073] The term “determining” encompasses a wide variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database, or another data structure), ascertaining and the like. Also, “determining” can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and the like. Also, “determining” can include resolving, selecting, choosing, establishing and the like.

[0074] The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed- 20 - 48623-00251-PCTelements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional implementations that also incorporate the recited features. For example, any element or feature described in relation to an embodiment herein may be combinable with any element or feature of any other embodiment described herein, where compatible.

[0075] The present disclosure may be embodied in other specific forms without departing from its spirit or characteristics. The described implementations are to be considered as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. Changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.- 21 - 48623-00251-PCT

Claims

CLAIMSWhat is claimed is:

1. A method for securing radio frequency (RF) communication in an RF communications contested area, the method comprising: generating wideband RF noise across a plurality of communication channels within an available RF spectrum for implementing communication channels in the RF communications contested area; attenuating the wideband RF noise within a selected communication frequency channel in the available RF spectrum; synchronizing the selected communication frequency channel with a transceiver; and transmitting a communication in the selected communication frequency channel.

2. The method of claim 1, wherein attenuating the wideband RF noise within the selected communication frequency channel comprises attenuating the wideband RF noise according to a dynamically adjustable center frequency and bandwidth for the selected communication frequency channel.

3. The method of claim 2, wherein the dynamically adjustable center frequency is adjusted to correspond to a frequency-hopping pattern of the transceiver.

4. The method of claim 1, wherein the wideband RF noise comprises pseudorandom noise waveforms.

5. The method of claim 1, wherein the wideband RF noise comprises white gaussian noise.

6. The method of claim 1, wherein generating wideband RF noise comprises directly synthesizing a wideband noise waveform via an integrated RF processing device.- 22 - 48623-00251-PCT7. The method of claim 1, wherein the selected communication frequency channel includes a plurality of communication frequency channels, and wherein attenuating the wideband RF noise includes attenuating the wideband RF noise across the plurality of communication frequency channels.

8. The method of claim 7, wherein transmitting the communication includes selecting a first communication frequency channel of the plurality of communication frequency channels for the communication and transmitting the communication includes transmitting the communication on the first communication frequency channel.

9. The method of claim 8, wherein the communication is a first communication, and further comprising: selecting a second communication frequency channel of the plurality of communication frequency channels; and transmitting a second communication on the second communication frequency channel.

10. The method of claim 1, wherein generating the wideband RF noise comprises increasing a power level of the wideband RF noise to at least the level of adversarial jamming signals.

11. The method of claim 1, wherein attenuating the wideband RF noise within the selected communication frequency channel comprises a bandwidth of less than 1 megahertz.

12. A system for securing radio frequency (RF) communication in an RF communications contested area, the system comprising: a wideband RF noise generator configured to generate RF noise across a plurality of communication channels within an RF spectrum available for implementing communication channels in the RF communications contested area; a filter configured to selectively attenuate the RF noise within a selected communication frequency channel to create a communication window; and- 23 - 48623-00251-PCTa transceiver configured to transmit a communication along the selected communication frequency channel while the wideband RF noise generator generates the RF noise.

13. The system of claim 12, wherein the transceiver is a frequency-agile transceiver.

14. The system of claim 12, further comprising a controller configured to: select a communication channel to attenuate the wideband RF noise within; and facilitate adjustment of the transceiver to the selected communication frequency channel.

15. The system of claim 14, wherein the controller includes a communication frequency channel selector configured to select the one of the plurality of communication frequency channels.

16. The system of claim 12, wherein the filter includes a notch filter.

17. The system of claim 12, further comprising a frequency agile receiver at a receiving device configured to receive the communication while the wideband RF noise generator generates wideband RF noise.

18. A transceiver for receiving secure RF communication in an RF communications contested area, comprising: a receiver configured to receive a communication along a communication frequency channel; and a receiver controller configured to: adjust the receiver to operate on a selected communication frequency channel corresponding to an attenuated wideband RF noise; and synchronize the receiver with a frequency -hopping pattern.

19. The transceiver of claim 18, wherein the receiver controller is configured to dynamically adjust a center frequency and bandwidth of the selected communication frequency channel.- 24 - 48623-00251-PCT20. The transceiver of claim 19, wherein the transceiver is a frequency-agile transceiver.- 25 - 48623-00251-PCT

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