System Level Performance Evaluation of Client Cooperation in Wireless Cellular Networks

Growing demand for bandwidth dictates the use of smaller wireless cells, which results in increased inter-cell interference. In most contemporary cellular systems, the clients at the cell edge typically have the worst chance of successful uplink transmission due to interference from the neighboring cells using the same frequency. Cooperative communications are believed to be a promising technique to enhance the performance of cell-edge users by allowing them to exploit other users as relay nodes and thus improve their throughput by reducing the number of retransmissions. This thesis presents in-depth system-level evaluation of client relay technique in state-of-the-art wireless cellular networks (IEEE 802.16, LTE release 10). Several important scenarios are considered, including opportunistic client relay behavior and various network layouts. It is demonstrated that client cooperation may considerably improve system performance in terms of cell-edge user performance for the cost of some increase in energy consumption of cell-center user. /Kir1

Modeling of SHF/EHF Radio-Wave Scattering for Curved Surfaces with Voxel Cone Tracing

Efficient and accurate radio propagation modeling is essential for optimization of both radio sensing and communication systems. However, highly accurate full-wave methods remain inefficient at high frequencies, as unit of computation (typically, a voxel) has to be made much smaller than the wavelength. On the other hand, ray-based approaches offer the desired speed, but the surface element (typically, a triangle) must be made much larger than the wavelength, making it difficult to represent complex curved surfaces of common objects such as cars or unmanned aerial vehicles. As a result, for SHF/EHF bands, it is challenging to select a method that is both fast and capable of capturing curved surfaces correctly. To address this matter, we present a method that offers a reasonable trade-off between speed and accuracy for radio propagation modeling in the bands of interest. Specifically, we combine efficient voxel scene representation targeting a cone tracing algorithm with a statistical scattering model. To confirm the validity of our approach, we report the dependence of reflected power on the distance for basic primitives such as cone and sphere, for which closed-form radar cross-section solutions are known.acceptedVersionPeer reviewe

Distributed Communication and Sensing System Co-Design for Improved UAV Network Resilience

The progress in wireless technology over the past decade led to the rapid adoption of Unmanned Aerial Vehicles (UAVs) for various applications. As the interest in UAVs is accelerating, increased attention is paid to the reliability and resilience of UAV-based systems with respect to the collision avoidance. One of the ways to improve this aspect is to utilize the RADAR functionality. In this work, we consider a cellular network employed for communication jointly with RADAR operation. The critical parameter that affects the RADAR algorithm is the radar cross-section (RCS). Since the task of obtaining the RCS of a complex-shaped object is extremely challenging, we first propose a novel, accurate, and fast method of scattered field assessment. We further perform radio network planning for the cellular deployment, as well as link budget estimations for the RADAR system that co-exists with it. Under this system model, we carry out detailed Monte-Carlo simulations of the RADAR detection process to obtain reliable statistical results and answer the question of how the actual bistatic RCS model affects the detection algorithm. We then apply mathematical modeling based on stochastic geometry to estimate the collision probability without the need to simulate an extensive number of flight-hours. Our numerical results confirm the robustness to RCS pattern nulls, which is crucial for safety-centric applications such as collision avoidance.acceptedVersionPeer reviewe

aColor: Mechatronics, Machine Learning, and Communications in an Unmanned Surface Vehicle

The aim of this work is to offer an overview of the research questions, solutions, and challenges faced by the project aColor ("Autonomous and Collaborative Offshore Robotics"). This initiative incorporates three different research areas, namely, mechatronics, machine learning, and communications. It is implemented in an autonomous offshore multicomponent robotic system having an Unmanned Surface Vehicle (USV) as its main subsystem. Our results across the three areas of work are systematically outlined in this paper by demonstrating the advantages and capabilities of the proposed system for different Guidance, Navigation, and Control missions, as well as for the high-speed and long-range bidirectional connectivity purposes across all autonomous subsystems. Challenges for the future are also identified by this study, thus offering an outline for the next steps of the aColor project.Comment: Paper was originally submitted to and presented in the 8th Transport Research Arena TRA 2020, April 27-30, 2020, Helsinki, Finlan

Future services and overlay architectures: State of the art report 1. UBISERVE project Deliverable D4.1

The UBISERVE-project (Research on Future Ubiquitous Services and Applications) is a joint research effort dedicated to advance research in the field of ubiquitous services. The project focuses on future services building on mobile communication systems and services. Within this Project, our aim in Work Package 4 is to develop an overall overlay architecture providing a rich set of service facilitators for mobile users of wireless convergence devices that contain hardware capabilities to accurately pinpoint their locations, possess multiple wireless interfaces and have large storage capacities. The architecture will also support contextually aware self-organising devices creating an on-demand, dynamic overlay, capable of supporting multipath, transport-independent communication among users and devices. Thus useful information needs to be gleaned from service providers, network operators, infrastructure, sensors and devices in the immediate operating environment. This State of the Art document is the first project document which analyses the key enabling technologies for service overlays, platforms, frameworks and communication mechanisms for creating such architectures that would prove indispensable in the creation of future services. In short, the following questions are examined: • What kinds of service overlays exist today? • How are service overlays relevant towards services in wireless devices? • What communication technologies can we expect future services to use? • What are the dominant development platforms for smartphone applications

System Level Performance Evaluation of Client Cooperation in Wireless Cellular Networks

Growing demand for bandwidth dictates the use of smaller wireless cells, which results in increased inter-cell interference. In most contemporary cellular systems, the clients at the cell edge typically have the worst chance of successful uplink transmission due to interference from the neighboring cells using the same frequency. Cooperative communications are believed to be a promising technique to enhance the performance of cell-edge users by allowing them to exploit other users as relay nodes and thus improve their throughput by reducing the number of retransmissions. This thesis presents in-depth system-level evaluation of client relay technique in state-of-the-art wireless cellular networks (IEEE 802.16, LTE release 10). Several important scenarios are considered, including opportunistic client relay behavior and various network layouts. It is demonstrated that client cooperation may considerably improve system performance in terms of cell-edge user performance for the cost of some increase in energy consumption of cell-center user. /Kir1

Future services and overlay architectures: State of the art report 1. UBISERVE project Deliverable D4.1

The UBISERVE-project (Research on Future Ubiquitous Services and Applications) is a joint research effort dedicated to advance research in the field of ubiquitous services. The project focuses on future services building on mobile communication systems and services. Within this Project, our aim in Work Package 4 is to develop an overall overlay architecture providing a rich set of service facilitators for mobile users of wireless convergence devices that contain hardware capabilities to accurately pinpoint their locations, possess multiple wireless interfaces and have large storage capacities. The architecture will also support contextually aware self-organising devices creating an on-demand, dynamic overlay, capable of supporting multipath, transport-independent communication among users and devices. Thus useful information needs to be gleaned from service providers, network operators, infrastructure, sensors and devices in the immediate operating environment. This State of the Art document is the first project document which analyses the key enabling technologies for service overlays, platforms, frameworks and communication mechanisms for creating such architectures that would prove indispensable in the creation of future services. In short, the following questions are examined: • What kinds of service overlays exist today? • How are service overlays relevant towards services in wireless devices? • What communication technologies can we expect future services to use? • What are the dominant development platforms for smartphone applications

Future services and overlay architectures: State of the art report 1. UBISERVE project Deliverable D4.1

The UBISERVE-project (Research on Future Ubiquitous Services and Applications) is a joint research effort dedicated to advance research in the field of ubiquitous services. The project focuses on future services building on mobile communication systems and services. Within this Project, our aim in Work Package 4 is to develop an overall overlay architecture providing a rich set of service facilitators for mobile users of wireless convergence devices that contain hardware capabilities to accurately pinpoint their locations, possess multiple wireless interfaces and have large storage capacities. The architecture will also support contextually aware self-organising devices creating an on-demand, dynamic overlay, capable of supporting multipath, transport-independent communication among users and devices. Thus useful information needs to be gleaned from service providers, network operators, infrastructure, sensors and devices in the immediate operating environment. This State of the Art document is the first project document which analyses the key enabling technologies for service overlays, platforms, frameworks and communication mechanisms for creating such architectures that would prove indispensable in the creation of future services. In short, the following questions are examined: • What kinds of service overlays exist today? • How are service overlays relevant towards services in wireless devices? • What communication technologies can we expect future services to use? • What are the dominant development platforms for smartphone applications