Journal Paper – Radio Lab

Heuristic method for relay node placement in heterogeneous wireless network

eguffens — Wed, 30 Apr 2025 14:00:41 +0000

Whether it is to initially deploy a network or to restore the connectivity in a partitioned one, the question of the optimal Relay Node (RN) placement arises. This problem is already challenging when considering a static homogeneous network. However, diversity in transmission parameters within the network can induce diversity in transmission ranges, imposing the consideration of heterogeneity in the network. Furthermore, if the nodes are moving, the RN placement scheme must manage a smooth repositioning of the RNs without any large jumps or major restructuring. This paper introduces an effective strategy for deploying the minimum number of RNs in order to restore the connectivity between the nodes of a partitioned heterogeneous network. Through the statistical analysis of results from numerous randomly generated scenarios, the proposed Barycenter-focused Relay nodes placement for Heterogeneous wireless Networks (BRHEN) algorithm is shown to be an improvement on other similar approaches in terms of the number of RNs and the latency. Additionally, BRHEN exhibits stability in the positions and number of RNs when small displacements are applied to the Initial Nodes (INs). This characteristic makes this method suitable for scenarios with moving INs.

Link to the paper

Researcher

Eliott Guffens

Project

DAP21-06

Wideband Cooperative Jamming with Band-Limited Known-Interference Cancellation

eguffens — Wed, 22 Jan 2025 13:30:53 +0000

Secure and reliable communications are vital to defense forces in achieving operational goals. Likewise, limiting the opponents’ capabilities to communicate further advances the host forces’ chances of operational success. In this work, we propose a method to fortify the host forces’ wireless communications against adversarial attacks while at the same time restricting the opponents’ capabilities to wirelessly communicate. That is, we propose a band-limited known-interference cancellation (KIC) method that enables the host forces to cover a large portion of the electromagnetic spectrum with wideband jamming, yet lets the host force communication nodes cancel that jamming signal upon reception even if the nodes only receive a narrowband portion of it. We study how the proposed KIC method works based on measurements with commercial off-the-shelf software-defined radios. The results demonstrate that the band-limited KIC method achieves performance that is comparable to non-band-limited methods and, in doing so, leads the way for practical applications of cooperative jamming in scenarios where narrowband communication links span over a wide bandwidth.

Link to the paper

Researcher

Vincent Le Nir

Project

LORACO

A Multispectral Camouflage Net Evaluation Capability

eguffens — Tue, 01 Oct 2024 14:08:00 +0000

The need for standardized guidelines and common evaluation techniques for assessing camouflage nets represents a challenge for the military operational community. This paper proposes a laboratory assessment methodology for the evaluation of camouflage nets. This method aims to be an accurate initial assessment before field tests, as the final stages for camouflage evaluation. Furthermore, it is more convenient to standardize laboratory indoor setups as the initial step because parameters can be controlled with precise equipment, eliminating any unexpected technical variables. Our approach combines radar testing in a semi-anechoic chamber and EO/IR (Electro-Optical/Infra-Red) assessment using an indoor laboratory setup. This method offers a more comprehensive and accurate evaluation compared to methods that focus on a single type of test. Following this procedure, we can assess the performance characteristics of camouflage nets by determining their behavior in all spectral domains associated with surveillance optical and radar equipment. For the EO/IR devices, we are interested in analyzing the nets in the 0.35 – 2.5 μm wavelength band, and both the Mid-Wave Infra-Red (MWIR) 3 – 5 μm and Long-Wave Infra-Red (LWIR) 8 – 12 μm thermal infrared transmission bands. For the radar systems, we focus on the X-band frequency in the range of 9 GHz to 11 GHz. The paper presents the results obtained by measuring three different multispectral camouflage net samples. It is shown that Samples Under Test (SUT) have relatively consistent average radar transmission attenuation with a small range of 2.22 dB. Furthermore, the average attenuation values vary between 3.3 dB and 14.71 dB when the camouflage net is rotated for further evaluation. Moreover, radar reflection results characterized by reflection coefficient values, standard deviation, mean, and Coefficient of Variation (CV), show that all samples, regardless of orientation, deviate from the consistent reference data of ten runs. In the thermal infrared domain, the nets are similar in terms of solar loading, showing a similar temperature increase of 8 ±1°C, but the transmission levels are different, between 11.7% and 21.8%. As for the reflectance measurements, the three SUT show different behaviors in terms of reflectance levels and contrast patterns, especially in the near and shortwave infrared bands of the EO domain.

Link to paper

Researcher

Radouane Karli

Project

DAP22-07

Spectrum Prediction for Protocol-Aware RF Jamming

eguffens — Mon, 01 Apr 2024 13:26:00 +0000

Neutralizing a drone using a protocol-aware RF jammer requires precise knowledge of the occupied spectrum in the time and frequency domains. This paper aims to develop an automatic spectrum prediction framework utilizing the Convolutional Neural Network (CNN) and Long Short Term Memory (LSTM) models. We generate a synthetic dataset using the commonly used drone signal properties and parameters, and evaluate the prediction performance under several realistic scenarios. Our experiment shows that the CNN-LSTM model can accurately predict future time and frequency sequences by using the spectrogram matrix as the input. We obtained better prediction performance with lower computational costs with our framework compared to the existing frameworks. Furthermore, we show that the CNN-LSTM model can predict future time-frequency sequences of unseen hopping rates and patterns when using transfer learning. The performance validation is also performed using real drone RF signals. Furthermore, we present a two-stage spectrum prediction approach that achieves excellent performance by offering higher frequency resolutions while maintaining a lower computational cost.

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Researcher

Sanjoy Basak

Project

AIRFORC

Dynamic Spectrum Management and Routing Solutions for Multi-Radio Mobile Ad Hoc Networks

eguffens — Tue, 28 Nov 2023 15:11:00 +0000

The electromagnetic spectrum’s scarcity, the tactical edge’s dynamic nature, and the variety of tactical operations impose challenges to military cognitive radio networks. Multi-radio dynamic spectrum management (DSM) and routing promise to increase the spectral efficiency and robustness of tactical ad hoc networks by adding key control plane tools that adapt the network to the varying harsh tactical environments. This paper describes a novel concept where implicit spectrum sensing, a distributed DSM architecture with ontology-based spectrum access policies, modified routing and network time synchronization capabilities interplay to address those challenges. The simulation results verify the designed functionality in harsh electromagnetic environments in a multitude of scenario sizes, in terms of number of radio terminals and number of networks. In particular, the simulation of a large operational scenario shows solid scaling capabilities and that ongoing jamming in several networks is efficiently mitigated and low-loss performance are re-established.

Link to the paper

Researcher

Vincent Le Nir

Project

DAP21-01

Physical-Layer Reliability of Drones and Their Counter-Measures: Full Versus Half Duplex

eguffens — Thu, 06 Jul 2023 13:06:00 +0000

In this article, we study the advantages and disadvantages that full-duplex (FD) radio technology brings to remote-controlled drone and counter-drone systems in comparison to classical half-duplex (HD) radio technology. We consider especially the physical-layer reliability perspective that has not yet been comprehensively studied. For establishing a solid analytical background, we first derive original closed-form expressions to evaluate demodulation and detection performance of frequency-hopped and frequency-shift keyed drone remote control signals under external or self-inflicted interference. The developed analytical tools are verified by comparison to simulated results and then used to study the impact that the operation mode has on the operable area of drones and effectiveness of counter-drone systems in different scenarios, linking the physical layer performance to practical safety. Analysis of the scenarios shows that FD operation compared to HD can improve the effectiveness of a counter-drone system and that in FD mode a drone can detect the attacks from the counter-drone system from a greater distance than in HD mode. However, two-way communication between the remote controller and drone in FD mode compared to HD significantly reduces the drone’s operable area when targeted by a smart counter-drone system.

Link to the paper

Researcher

Vincent Le Nir

Project

LORACO