arXiv subjects

Danny Hughes

Publications and source records attributed to Danny Hughes.

7 recordsLinked to original sources

arXiv2026

RF-Zero-Wire: Design and Analysis of Multi-Hop Low-latency Symbol-synchronous RF Communication

The latency gap between wired and wireless networks poses a challenge in the adoption of wireless technologies in latency-sensitive scenarios. The gap is especially notable in multi-hop communication typical for industrial sensor networks and robotic swarms. The main reason behind it is that commonly used wireless protocols rely on store-and-forward routing and costly overhead procedures to avoid interference. This article introduces RF-Zero-Wire, an RF-based symbol-synchronous communication protocol. Instead of relaying the whole frame per hop in a store-and-forward manner, nodes concurrently relay the frame symbol by symbol, without the need for tight time synchronization. Based on data collected in real-world experiments, we reveal that the inevitable carrier frequency offsets (CFOs) introduced by imperfect crystal oscillators cause a beating effect under concurrent symbol transmissions. This is characterized by periodic constructive and destructive interference, which significantly affects reliability. Subsequently, a thorough simulation study shows how the beating problem can be overcome with error correction codes. RF-Zero-Wire allows achieving an end-to-end latency of less than 1ms for a small 4-byte frame transmitted across 5 hops. Moreover, latency is shown to increase only by 0.16% per extra hop for 16-byte frames, which is negligible compared to the over 100% per-hop latency increase observed in store-and-forward protocols. The trade-offs between network reliability and CFO range, communication distance, node density, and achievable data rate are studied in large-scale experiments based on simulation.

cs.NI↗

arXiv2026

Silicone Ethernet (SEth): a Nervous System for Robotic Touch

Fine-grained robotic touch sensing is essential for tasks such as robot-human interaction and the handling of hazardous materials. Yet, the sense of touch of robots is limited by the cost and complexity of routing cables to embedded sensors. This paper tackles this problem by contributing Silicone Ethernet (SEth), a wireless solution for touch sensing, communication and power transfer within a conductive silicone substrate. SEth~\emph{neurons} require no battery and deliver computation, communication, sensing and energy harvesting within a compact package. These neurons are placed into an undifferentiated conductive silicone substrate which may form the entire body of a soft robot, or an outer `skin' for hard robots. Our evaluation shows that SEth achieves data rates of 100\,kbps with sub-$\mu$W receive and mW-scale transmit power. Exploiting the unique properties of the conductive silicone substrate, SEth provides prioritized traffic arbitration similar to that found in wired control networks such as CAN. The SEth network inherently supports capacitive touch and presence sensing and neurons can harvest sufficient energy to transmit 10s of messages per second at a range of 1\,m. Considered in sum, these features open new degrees of freedom in touch sensing for soft robots.

cs.NI↗

arXiv2024

Low-latency Symbol-Synchronous Communication for Multi-hop Sensor Networks

Wireless sensor networks (WSNs) have received great interest due to their scalability, energy efficiency, and low-cost deployment. By utilizing multi-hop communication, WSNs can cover a wide area using low transmission power without the need for any communication infrastructure. Traditionally, WSNs rely on store-and-forward routing protocols and Time Division Multiple Access (TDMA)-based schedules that avoid interference between different wireless nodes. However, emerging challenging scenarios, such as the industrial Internet of Things (IoT) and robotic swarms, impose strict latency and reliability requirements, which traditional approaches cannot fulfill. In this paper, we propose a novel symbol-synchronous transmission design that provides reliable low-latency communication with a reasonable data rate on classical sub-6GHz RF frequency bands (e.g., the 2.4GHz ISM band). Instead of avoiding overlapping transmissions, the proposed scheme benefits from concurrent transmissions. Using simulation in MATLAB, we prove that the proposed design allows achieving a wire-like delay of 5ms for a 512-bit packet over multiple hops with only a 0.3% latency increase per extra hop and a low bit error rate (BER) of 0.04%. Compared to similar state-of-the-art approaches it can achieve a significantly higher data rate of 100kbps, which is expected to increase further with future improvements of the system.

cs.NI↗

arXiv2024

ConvDTW-ACS: Audio Segmentation for Track Type Detection During Car Manufacturing

This paper proposes a method for Acoustic Constrained Segmentation (ACS) in audio recordings of vehicles driven through a production test track, delimiting the boundaries of surface types in the track. ACS is a variant of classical acoustic segmentation where the sequence of labels is known, contiguous and invariable, which is especially useful in this work as the test track has a standard configuration of surface types. The proposed ConvDTW-ACS method utilizes a Convolutional Neural Network for classifying overlapping image chunks extracted from the full audio spectrogram. Then, our custom Dynamic Time Warping algorithm aligns the sequence of predicted probabilities to the sequence of surface types in the track, from which timestamps of the surface type boundaries can be extracted. The method was evaluated on a real-world dataset collected from the Ford Manufacturing Plant in Valencia (Spain), achieving a mean error of 166 milliseconds when delimiting, within the audio, the boundaries of the surfaces in the track. The results demonstrate the effectiveness of the proposed method in accurately segmenting different surface types, which could enable the development of more specialized AI systems to improve the quality inspection process.

cs.SD↗

arXiv2022

A Survey of Security and Privacy Issues in V2X Communication Systems

Vehicle-to-Everything (V2X) communication is receiving growing attention from industry and academia as multiple pilot projects explore its capabilities and feasibility. With about 50\% of global road vehicle exports coming from the European Union (EU), and within the context of EU legislation around security and data protection, V2X initiatives must consider security and privacy aspects across the system stack, in addition to road safety. Contrary to this principle, our survey of relevant standards, research outputs, and EU pilot projects indicates otherwise; we identify multiple security and privacy related shortcomings and inconsistencies across the standards. We conduct a root cause analysis of the reasons and difficulties associated with these gaps, and categorize the identified security and privacy issues relative to these root causes. As a result, our comprehensive analysis sheds lights on a number of areas that require improvements in the standards, which are not explicitly identified in related work. Our analysis fills gaps left by other related surveys, which are focused on specific technical areas but not necessarily point out underlying root issues in standard specifications. We bring forward recommendations to address these gaps for the overall improvement of security and safety in vehicular communication.

cs.CR↗

arXiv2020

Tackling Contention Through Cooperation: A Distributed Federation in LoRaWAN Space

Low-Power Wide Area Networks (LPWAN) play a key role in the IoT marketplace wherein LoRaWAN is considered a leading solution. Despite the traction of LoRaWAN, research shows that the current contention management mechanisms of LoRaWAN do not scale. This paper tackles contention on LoRaWAN by introducing FLIP, a fully distributed and open architecture for LoRaWAN that fundamentally rethinks how LoRa gateways should be managed and coordinated. FLIP transforms LoRa gateways into a federated network that provides inherent support for roaming while tackling contention using consensus-driven load balancing. FLIP offers identical security guarantees to LoRaWAN, is compatible with existing gateway hardware and requires no updates to end-device hardware or firmware. These features ensure the practicality of FLIP and provide a path to its adoption. We evaluate the performance of FLIP in a large-scale real-world deployment and demonstrate that FLIP delivers scalable roaming and improved contention management in comparison to LoRaWAN. FLIP achieves these benefits within the resource constraints of conventional LoRa gateways and requires no server hardware.

cs.NI↗

arXiv2017

Selective Jamming of LoRaWAN using Commodity Hardware

Long range, low power networks are rapidly gaining acceptance in the Internet of Things (IoT) due to their ability to economically support long-range sensing and control applications while providing multi-year battery life. LoRa is a key example of this new class of network and is being deployed at large scale in several countries worldwide. As these networks move out of the lab and into the real world, they expose a large cyber-physical attack surface. Securing these networks is therefore both critical and urgent. This paper highlights security issues in LoRa and LoRaWAN that arise due to the choice of a robust but slow modulation type in the protocol. We exploit these issues to develop a suite of practical attacks based around selective jamming. These attacks are conducted and evaluated using commodity hardware. The paper concludes by suggesting a range of countermeasures that can be used to mitigate the attacks.

cs.NI↗