Control systems and methods to secure communications within the control system. The control system includes a control node operably coupled to a concentrator node via a first data link. The control node can communicate with the concentrator node over the first data link at a first communication frequency and first communication rate. The control node can also change the first communication frequency in response to an event, such as a cyber-security threat. The concentrator node can communicate with the control node at the changed first communication frequency in response to receiving a frequency change indication. In some examples, the control node is also operably coupled to the concentrator node via a second data link. The second data link may operate at a second communication rate that is different from the first communication rate. The control node may send redundant data on the first data link and the second data link.

A communication device includes a first module, a communication portion communicating with a second module, a memory, and a processor that executes instructions stored in the memory. The instructions cause the processor to perform: executing a processing of changing a first radio communication to a non-restrictive state when a first signal is received from the second module in a state that the first radio communication is in a restrictive state; and executing a first processing of transmitting a second signal for changing a second radio communication to the non-restrictive state to the second module and a second processing of changing the first radio communication to the restrictive state when the priority signal using the first channel is detected in a state that the first radio communication is in the non-restrictive state.

An access point in a wireless network communicates wirelessly with one or more client devices over a channel that includes a plurality of subchannels. Each subchannel corresponds to a distinct frequency chunk with a respective plurality of subcarriers. Radar is detected on a first subchannel. In response, a selection is made between (i) redefining the channel and (ii) puncturing the first subchannel while continuing to use all other subchannels. Puncturing the first subchannel includes muting subcarriers on the first subchannel. Redefining the channel includes removing multiple subchannels from the channel. The selection is based at least in part on one or more factors that provide indications as to whether puncturing would be efficient and/or effective. The access point continues to communicate wirelessly with the one or more client devices in accordance with the selection.

Methods, systems, and apparatus, including computer programs encoded on a storage device, for triggering an alarm during a sensor jamming attack. In one aspect, a monitoring system sensor unit is disclosed that includes a sensor, a communication unit configured to communicate with a monitoring system using a range of frequencies, and a jamming detection unit. The jamming detection unit may include a processor and a computer storage media storing instructions that, when executed by the processor, cause the processor to perform operations. The operations include detecting a sensor jamming event, selecting a different form of communication other than the range of radio frequencies for the communication unit to communicate with the monitoring system, and providing, to the communication unit, an instruction to communicate with the monitoring system using the form of communication, wherein the communication unit may communicate, to the monitoring system using the form of communication, the sensor data.

Methods and apparatus for performing automatic gain control (AGC) in bypass and filter modes for radio frequency (RF) front-end circuitry are described. An example method includes operating a receiver in a first mode during a first set of symbols of a first subframe. The method also includes, during a first symbol of the first subframe outside the first set of symbols, determining whether to operate the receiver in the first mode or a second mode in a second subframe, based at least in part on an output of a jamming detection circuit of the receiver in the first symbol. The method also includes controlling the receiver to operate in the first mode or the second mode in the second subframe, in accordance with the determination.

A threat monitoring and vulnerability management system is disclosed. The system includes one or more sensors configured to scan a frequency spectrum of a project 25 (P25) network and to collect data on the P25network. The system further includes a server coupled to the sensors and configured to receive the collected data from the plurality of sensors, compare the collected data with previously stored historical data to determine whether an anomaly exists within data patterns of the collected data, responsive to determining that the anomaly exists, determine at least one of: whether use of a cloned radio that mimics an authorized connection occurs, whether jamming of a radio frequency (RF) communication occurs, or whether jamming of a voice communication occurs within the P25 network by comparing the collected data with preset thresholds, and send a real-time alert to a dispatch and control console unit coupled to the server and the P25 network in response to determining that some of the collected data exceeds at least one of the preset thresholds, such that the dispatch and control console unit provides one or more corrective actions to the P25 network.

A method for a user equipment operating in a cellular network having a plurality of base stations, the user equipment operating on at least one of the base stations, hereinafter the serving base station, for the case of a communication loss to its serving base station, whereby the conditions relating to the serving base station or the corresponding frequency fulfills the criteria concerning jamming. The method includes the steps of: scanning for accessible base stations of the cellular network, examining the at least one base station being identified through the scanning step, by means of signalling message, evaluating the response behavior of the at least one base station, wherein in consideration of the response behavior of at least one of said base station if said base station is rated as suspicious: indicating a jamming situation, otherwise camping on at least one of the base stations.

A navigation method based on satellite and inertial positioning data includes the following steps of computing: a first reference navigation, that is hybridised on the basis of inertial positioning data with positional corrections determined on the basis of satellite positioning data; a second reference navigation, that is hybridised on the basis of inertial positioning data; an emergency navigation on the basis of the second reference navigation, reset on the operational navigation then corrected by means of the positional corrections provided by the first reference navigation. A navigation system for implementing this method is also disclosed.

A secure wireless transceiver, such as a link 16 transceiver, receives signals using an antenna array having an SOC associated with each antenna element in the array. The SOC's digitize and channelize received data for transmission to a message nulling system that mitigates jamming. The antenna array can be conformal, and can replace an existing Link 16 blade. The disclosed transceiver can be a modified CMN-4 transceiver with digitizing and channelizing moved to the SoC's, and replaced by the nulling system. The transceiver uses applicable TRANSEC information to assign received data to the logical Link 16 channels before nulling, and embodiments apply nulling only to channels of interest, thereby improving the nulling and reducing side lobes. Embodiments distinguish between desired and unwanted signals based on known Link 16 signal features and/or situational awareness, rather than signal amplitudes, thereby enabling nulling of even weak jamming signals.

A wireless communication system having base stations, remotely located terminal units and a base station controller. The base stations and the remotely located terminal units communicate data over operational wireless communication links between them. The base stations include respective in-channel detectors and out-of-channel detectors for detecting radar or other extraneous received signals. The in-channel detectors analyse signals over the operational communication links. The out-of-channel detectors include respective out-of-channel receiver elements that monitor possibly available channels alternative to the respective operational communication link channels. The base station controller registers whether channels are available or not for communication links, and allocates to the base stations respective target channel parameters including frequencies available for operational and alternative communication links. The base stations store the respective target channel parameters for available operational and alternative communication links.