Akram Al-Hourani

• PhD, BEng, MBA, SMIEEE
• Professor at RMIT University

In this paper we present an analytic framework for formulating the statistical distribution of the nearest neighbour distance in hard-core point processes. We apply this framework to Matérn hard-core point process (MHC) to derive the cumulative distribution function of the contact distance in three cases. The first case is between a point in an MHC...

Aerial platforms have recently gained a significant popularity as key enablers for rapid deployable relief networks where coverage is provided by onboard radio heads. These platforms are capable of delivering essential wireless communication for public safety agencies in remote areas or during the aftermath of natural disasters. In this paper we pr...

In this paper we provide an analytic framework for computing the expected downlink coverage probability, and the associated rate of cellular networks, where base stations are distributed in a random manner . The provided expressions are in computable integral forms that accommodate generic channel fading conditions. We develop these expressions by...

This paper lays a mathematical framework for estimating the energy saving of a relay assisting a pair of wireless devices. We derive closed-form expressions for describing the geometrical zone where relaying is energy efficient. In addition, we obtain the probabilistic distribution of the energy saving introduced by relays that are randomly distrib...

With the unprecedented new capabilities introduced by modern broadband wireless networks, public safety agencies are increasingly depending on such networks for their mission critical communications. One of the key enablers for this adoption is the Device to Device (D2D) communication, where mobiles can connect directly between each others, without...

Passive synthetic aperture radar (SAR) has attracted research in recent years because of its advantages in exploiting opportunistic signals for imaging. Hence, it minimizes the need for active radar transmitters, significantly reducing system costs. In addition, the massive proliferation of telecommunication satellites in recent years motivates the...

The radio frequency (RF) spectrum is a scarce natural resource utilized by terrestrial and satellite systems that operate in regulated frequency bands. The sharing of this scarce resource and the bandwidth of these systems has led to various types of interferences including, narrowband interference (NBI) and wideband interference (WBI). The spectru...

With the expansive deployment of ground base stations, low Earth orbit (LEO) satellites, and aerial platforms such as unmanned aerial vehicles (UAVs) and high altitude platforms (HAPs), the concept of space-air-ground integrated network (SAGIN) has emerged as a promising architecture for future 6G wireless systems. In general, SAGIN aims to amalgam...

This paper presents a method for autonomously searching for a Radio Frequency (RF) emitter within an indoor environment. It uses a cognitive search strategy to locate an RF emitter at discrete intervals. This capability is lacking in traditional methods due to their inability to adapt in real-time, utilize information efficiently, and handle comple...

Doppler shift has significant implications in Low Earth Orbit (LEO) constellations due to the rapid relative movement of satellites. This paper presents a novel approach based on stochastic geometry to capture the statistical distribution of Doppler shift in modern mega satellite constellations. We derive a simplified expression for both the Dopple...

With near-Earth space becoming increasingly congested , the threat of satellite collisions escalates. Existing collision avoidance methods heavily rely on ground-based radar measurements to determine the ephemeris of space objects and dictate maneuvering commands. This paper introduces a method that proposes estimating the miss distance between two...

Transmitter authentication is critical for secured Internet of Things (IoT) applications. Recently, there has been growing interest in utilizing the physical layer authentication technique, radio frequency (RF) fingerprinting, to introduce extra security measurements without adding additional components. This work presents a novel fingerprint explo...

As the Internet of Things (IoT) applications continue to experience exponential growth, the resulting congestion in frequency spectrum highlights the necessity for innovative spectrum monitoring techniques. Spectrum sensing plays a crucial role in cognitive radio systems by facilitating the efficient utilization of spectrum through the detection an...

Radio Frequency Interference (RFI) in Synthetic Aperture Radar (SAR) is a daunting challenge that affects the SAR sensing reliability and its image quality. To ensure that SAR remains a powerful tool for Earth observation, this paper presents an effective two-dimensional tuneable attenuation space-frequency (azimuth-range) filtration. This framewor...

With the exponential growth of the Internet of Things (IoT) landscape and the resulting spectrum congestion, innovative techniques for spectrum monitoring are crucial. This paper presents an approach to spectrum monitoring harnessing the power of spiking neural networks (SNNs) with a focus on image segmentation using the UNet architecture. Traditio...

The efficient utilization of limited spectral resources in space presents a significant challenge given the rapidly increasing number of satellites (SATs) in various orbits. To address this challenge, it is paramount to enhance spectral efficiency by facilitating inter-operation between SATs in different orbits. In this letter, we investigate the i...

Modeling the stochastic behavior of Line-of-Sight (LoS) availability holds significant importance in evaluating the performance of non-terrestrial networks (NTN), encompassing both satellite and UAV links. This paper presents a novel framework for quantifying LoS probability in diverse urban settings, utilizing a practical visual (camera-based) app...

The proliferation of the Internet of Things (IoT) has created significant opportunities for future telecommunications. A popular category of IoT devices is oriented toward low-cost and low-power applications. However, certain aspects of such category, including the authentication process, remain inadequately investigated against cyber vulnerabiliti...

Earth observation has a crucial role in understanding and monitoring our planet's health and changes. Spaceborne Synthetic Aperture Radar (SAR) has become a valuable technology for Earth monitoring, leading to a massive expansion of satellite launches. However, within the limited radio frequency (RF) band, Radio Frequency Interference (RFI) poses a...

Radio Frequency Interference (RFI) in Synthetic Aperture Radar (SAR) is a daunting challenge, affecting both sensing reliability and image quality. To ensure that SAR remains a powerful tool for Earth observation, this paper presents a two-dimensional variable attenuation space (azimuth)-frequency filtration (VASFF) method. This framework leverages...

Utilizing Low Earth Orbit (LEO) satellite networks equipped with Inter-Satellite Links (ISL) is envisioned to provide lower delay compared to traditional optical networks. However, LEO satellites have constrained energy resources as they rely on solar energy in their operations. Thus requiring special consideration when designing network topologies...

Non-terrestrial networks have been gaining momentum in recent years as an integral part of current 3GPP releases and future networks. It is imperative to capture the intrinsic features of the Unmanned Aerial Non-terrestrial networks have been gaining momentum in recent years as an integral part of current 3GPP releases and future networks. It is im...

While global navigation satellite system (GNSS) technologies have always been the go-to solution for localization problems, they may not be the best choice for some Internet-of-Things (IoT) applications due to the incurred power consumption and cost. In this paper, we present an alternative satellite-based localization method exploiting the signatu...

Internet-of-things (IoT) is a widely used term that refers to a large ecosystem of integrated technologies, one of which is the wireless access system that connects remote devices to the network. This paper presents a framework for developing industry-focused wireless access systems for IoT that balances today's industry needs with future innovatio...

With the rapid growth of Internet of Things (IoT) networks, ubiquitous coverage is becoming increasingly necessary. Low Earth Orbit (LEO) satellite constellations for IoT have been proposed to provide coverage to regions where terrestrial systems cannot. However, LEO constellations for uplink communications are severely limited by the high density...

Earth observation has a crucial role in understanding and monitoring our planet's health and changes. Spaceborne Synthetic Aperture Radar (SAR) has become a valuable technology for Earth monitoring, leading to a massive expansion of satellite launches. However, within the limited radio frequency (RF) band, Radio Frequency Interference (RFI) poses a...

Earth observation has a crucial role in understanding and monitoring our planet's health and changes. Spaceborne Synthetic Aperture Radar (SAR) has become a valuable technology for Earth monitoring, leading to a massive expansion of satellite launches. However, within the limited radio frequency (RF) band, Radio Frequency Interference (RFI) poses a...

p>Mega satellite networks recently emerged to complement the current terrestrial infrastructure to attain global coverage and faster communication links. However, with increased congestion in the radio spectrum, migrating satellite communication to high frequencies can provide higher data rates. Nevertheless, signal fading due to weather conditions...

p>Mega satellite networks recently emerged to complement the current terrestrial infrastructure to attain global coverage and faster communication links. However, with increased congestion in the radio spectrum, migrating satellite communication to high frequencies can provide higher data rates. Nevertheless, signal fading due to weather conditions...

Earth observation has a crucial role in understanding and monitoring our planet's health and changes. Spaceborne Synthetic Aperture Radar (SAR) has become a valuable technology for Earth monitoring, leading to a massive expansion of satellite launches. However, within the limited radio frequency (RF) band, Radio Frequency Interference (RFI) poses a...

With the exponential growth of the Internet of Things (IoT) landscape and the resulting spectrum congestion, innovative techniques for spectrum monitoring are crucial. This paper presents a groundbreaking approach to spectrum monitoring harnessing the power of spiking neural networks (SNNs) with a focus on image segmentation using the UNet architec...

With the exponential growth of the Internet of Things (IoT) landscape and the resulting spectrum congestion, innovative techniques for spectrum monitoring are crucial. This paper presents a groundbreaking approach to spectrum monitoring harnessing the power of spiking neural networks (SNNs) with a focus on image segmentation using the UNet architec...

p>This is a preprint of the paper, "Artificial Intelligence Techniques for Next-Generation Massive Satellite Networks".</p

Utilizing Low Earth Orbit (LEO) satellite networks equipped with Inter-Satellite Links (ISL) is envisioned to provide lower delay compared to traditional optical networks. However, LEO satellites have constrained energy resources as they rely on solar energy in their operations. Thus requiring special consideration when designing network topologies...

Utilizing Low Earth Orbit (LEO) satellite networks equipped with Inter-Satellite Links (ISL) is envisioned to provide lower delay compared to traditional optical networks. However, LEO satellites have constrained energy resources as they rely on solar energy in their operations. Thus requiring special consideration when designing network topologies...

Utilizing Low Earth Orbit (LEO) satellite networks equipped with Inter-Satellite Links (ISL) is envisioned to provide lower delay compared to traditional optical networks. However, LEO satellites have constrained energy resources as they rely on solar energy in their operations. Thus requiring special consideration when designing network topologies...

Devices authentication is one crucial aspect of any communication system. Recently, the physical layer approach radio frequency (RF) fingerprinting has gained increased interest as it provides an extra layer of security without requiring additional components. In this work, we propose an RF fingerprinting based transmitter authentication approach d...

Complementing RSSI measurements at anchors with onboard smartphone accelerometer measurements is a popular research direction to improve the accuracy of indoor localization systems. This can be performed at different levels; for example, many studies have used pedestrian dead reckoning (PDR) and a filtering method at the algorithm level for sensor...

Miniaturization and energy consumption by computational systems remain major challenges to address. Optoelectronics based synaptic and light sensing provide an exciting platform for neuromorphic processing and vision applications offering several advantages. It is highly desirable to achieve single‐element image sensors that allow reception of info...

Direction-of-arrival (DoA) estimation methods are highly versatile and find extensive applications in satellite communication. DoA methods are employed across a range of orbits, from low Earth orbits (LEO) to geostationary Earth orbits (GEO). They serve multiple applications, including altitude determination, geolocation and estimation accuracy, ta...

With advancements in computer processing power and deep learning techniques, hyperspectral imaging is continually being explored for improved sensing applications in various fields. However, the high cost associated with such imaging platforms impedes their widespread use in spite of the availability of the needed processing power. In this paper, w...

Random access schemes are widely used in IoT wireless access networks. They enable a reduced complexity and overcome power consumption constraints. Nevertheless, random access results in high packet losses which are caused by overlapping transmissions. Signal detection methods for digital modulation techniques are typically based on the well-establ...

The Direction-of-Arrival (DoA) estimation methods are highly versatile and find extensive applications in satellite communication. The DoA methods are employed across a range of orbits, from Low Earth Orbits (LEO) to Geostationary Earth Orbits (GEO). They serve multiple applications, including altitude determination, geolocation and estimation accu...

Macrophages are heterogeneous innate immune cells that are functionally shaped by their surrounding microenvironment. Diverse macrophage populations have multifaceted differences related to their morphology, metabolism, expressed markers, and functions, where the identification of the different phenotypes is of an utmost importance in modelling imm...

With the rapid growth of IoT networks, ubiquitous coverage is becoming increasingly necessary. Low Earth Orbit (LEO) satellite constellations for IoT have been proposed to provide coverage to regions where terrestrial systems cannot. However, LEO constellations for uplink communications are severely limited by the high density of user devices, whic...

Many Internet-of-Things (IoT)-over-satellite applications rely on affordable location-aware but energy-constrained IoT sensors. In this letter, we propose a novel method to estimate the satellite visibility window in IoT devices based on simple Doppler measurements. We present two scenarios where the orbital information of the serving satellite is...

Cardiovascular diseases are the leading cause of mortality, morbidity, and hospitalization around the world. Recent technological advances have facilitated analyzing, visualizing, and monitoring cardiovascular diseases using emerging computational fluid dynamics, blood flow imaging, and wearable sensing technologies. Yet, computational cost, limite...

As the number of satellite networks increases, the radio spectrum is becoming more congested, prompting the need to explore higher frequencies. However, it is more difficult to operate at higher frequencies due to severe impairments caused by varying atmospheric conditions. Hence, radio channel forecasting is crucial for operators to adjust and mai...

Space communications, particularly massive satellite networks, re-emerged as an appealing candidate for next generation networks due to major advances in space launching, electronics, processing power, and miniaturization. However, massive satellite networks rely on numerous underlying and intertwined processes that cannot be truly captured using c...

This paper presents a geometry-based three-dimensional Probability of Line of Sight (PLoS) model for generic urban environments. The existing PLoS models are mostly empirical, based on measurements or ray-tracing simulations at specific environments. To enable Unmanned Aerial Vehicle (UAV) communication in various environments, it is urgently neces...

Macrophages are heterogeneous innate immune cells that are functionally shaped by their surrounding microenvironment. Diverse macrophage populations have multifaceted differences related to their morphology, metabolism, expressed markers, and functions, where the identification of the different phenotypes is of an utmost importance in modelling imm...

p>Many Internet-of-Things (IoT)-over-satellite applications rely on affordable location-aware but energy-constrained IoT sensors. In this paper, we propose a novel method to estimate the satellite visibility window in IoT devices based on simple Doppler measurements. We present two scenarios where the orbital information of the serving satellite's...

Many Internet-of-Things (IoT)-over-satellite applications rely on affordable location-aware but energy-constrained IoT sensors. In this paper, we propose a novel method to estimate the satellite visibility window in IoT devices based on simple Doppler measurements. We present two scenarios where the orbital information of the serving satellite's is...

Low Earth orbit (LEO) satellite constellations are currently being explored to provide global and seamless coverage for IoT-over-Satellite applications. Random access techniques require low transmission overhead providing a compatible route for IoT-over-Satellite applications, however, coming at the expense of the offered quality-of-service. In thi...

p>While global navigation satellite system (GNSS)technologies have always been the go-to solution for localizationproblems, they may not be the best choice for some Internet-of-Things (IoT) applications due to the incurred power consumptionand cost. In this paper, we present an alternative satellite-basedlocalization method exploiting the signature...

While global navigation satellite system (GNSS) technologies have always been the go-to solution for localization problems, they may not be the best choice for some Internet-of-Things (IoT) applications due to the incurred power consumption and cost. In this paper, we present an alternative satellite-based localization method exploiting the signatu...

p>This paper presents a practical approach for Q/V-band modeling for low Earth orbit satellite channels based on tools from machine learning and statistical modeling. The developed Q/V-band LEO satellite channel model is presented in two folds; (i) a real-time forecasting method using model-based deep learning, intended for real-time operation of s...

p>This paper presents a practical approach for Q/V-band modeling for low Earth orbit satellite channels based on tools from machine learning and statistical modeling. The developed Q/V-band LEO satellite channel model is presented in two folds; (i) a real-time forecasting method using model-based deep learning, intended for real-time operation of s...

Space communications, particularly mega satellite networks, re-emerged as an appealing candidate for next generation networks due to major advances in space launching, electronics, processing power, and miniaturization. However, mega satellite networks rely on numerous underlying and intertwined processes that cannot be truly captured using convent...

Air-writing is an emerging and promising method for contactless human-machine interaction. This paper proposes a novel air-writing framework based on a single ultra wide-band radar (UWB). The framework employs a simple data capture and a processing pipeline facilitated by deep learning approaches, where a number of data representations and models a...

For the easy and flexible management of large scale networks, Software-Defined Networking (SDN) is a strong candidate technology that offers centralisation and programmable interfaces for making complex decisions in a dynamic and seamless manner. On the one hand, there are opportunities for individuals and businesses to build and improve services a...

Determining the location of wireless devices is vital in many applications. However, global navigation satellite system technologies require a dedicated hardware module installed in the device, imposing additional power and cost constraints. This paper presents a framework to passively localize ground wireless devices by a constellation of satellit...

Recent satellite constellations are being deployed to serve massive numbers of wireless devices, especially targeting those located in rural and offshore settings. Accordingly, business models relying on data reported via wireless Internet-of-Things (IoT) networks can now easily utilize satellite constellations to expand their offerings. In this pa...

Dense satellite constellations recently emerged as a prominent solution to complementing terrestrial networks in attaining true global coverage. As such, analytic optimization techniques can be adopted to rapidly maximize the benefits of such satellite networks. The paper presents a framework that relies on two primary tuning parameters to optimize...

Digital connectivity has become the foundation of prosperity and an essential need for functioning societies. Despite this dependence, limitation on Internet access remains a prevalent issue, largely hinging on socioeconomic and geographic factors. A promising solution to attain global access equality is based on integrated terrestrial-satellite ne...

Through Non-Terrestrial Networks (NTN), a global coverage connecting areas with minimal or no terrestrial services is envisaged using satellite and air-borne platforms. However, one of the challenges to delivering NTN communications is the increased levels of path-loss, relative to typical terrestrial scenarios, due to the vast communication distan...

In recent years, radar sensors are gaining a paramount role in non-invasive inspection of different objects and materials. In this paper, we present a framework for using machine learning in material identification based on their reflected radar signature. We employ multiple receiving channels of the radar module to capture the signatures of the re...

Novel Internet-of-Things (IoT) access technologies are emerging as part of the next generation cellular networks. These technologies are specifically oriented towards energy-limited IoT devices that are scattered far away from their serving base station. One of the key methods of achieving deep coverage is via repeated transmissions of data. Howeve...

Random access schemes are widely used in IoT wireless access networks to accommodate simplicity and power consumption constraints. As a result, the interference arising from overlapping IoT transmissions is a significant issue in such networks. Traditional signal detection methods are based on the well-established matched filter using the complex c...

Anomalies could be the threats to the network that has ever/never happened. To detect and protect networks against malicious access is always challenging even though it has been studied for a long time. Due to the evolution of network in both new technologies and fast growth of connected devices, network attacks are getting versatile as well. Compa...

Dense satellite constellations recently emerged as a prominent solution to complementing terrestrial networks in attaining true global coverage. As such, analytic optimization techniques can be adopted to rapidly maximize the benefits of such satellite networks. The paper presents a framework that relies on two primary tuning parameters to optimize...

Radio Frequency (RF) fingerprinting is an emerging technology for advanced device authentication. In this work, we investigate the feasibility of utilizing three different types of fundamental waveform for the purpose of RF fingerprinting. The Short-time Fourier Transform (STFT) is adopted to exploit potential RF fingerprints, which results are the...

Low Earth Orbit (LEO) constellations offer superior low latency performance and excellent signal power, however because of satellites inherent fast relative movement, frequent handovers are necessary for maintaining a continuous connection in such constellations. This paper lays an analytic method for estimating the session duration between two con...

Miniature radar sensors typically excel in capturing radial movements, while the thermal sensor can easily capture lateral movements; this complementary nature motivates the fusion of measurements from both sensors for enhancing the accuracy of hand-gesture recognition. This paper presents fusion techniques for combining the signal from commerciall...

Denial of Service and Distributed Denial of Service (DoS/DDoS) attacks have been one of the biggest threats against communication networks and applications throughout the years. Modelling DoS/DDoS attacks is necessary to get a better understanding of their behaviour at each step of the attack process, from the Botnet recruitment up to the dynamics...