Real-time Communication Protocol Research Articles

Embedded Cyber-Physical System for Physiological Control of Ventricular Assist Devices

Ventricular Assist Devices (VADs) play a crucial role in both bridging to transplantation and serving as destination therapy for congestive heart failure (CHF) management. This study aims to address the limitations of existing control strategies for VADs, specifically their inability to adapt automatically to hemodynamic changes. It proposes a novel embedded cyber-physical system (CPS) based on real-time data processing, reconfigurable architecture, and communication protocols aligned with Health 4.0 concepts to enhance physiological control over VADs (PC-VAD). The research employs a multi-objective PC-VAD approach within a hybrid cardiovascular simulator. An embedded CPS is introduced to overcome challenges related to differences in controller characteristics between computers and embedded systems. The study assesses the performance of the embedded CPS by comparing it with a computer-based control system. The embedded CPS demonstrates outcomes comparable to the computer-based control system, maintaining mean arterial pressure and cardiac output at physiological levels. Even in the face of variations in ejection fraction, the embedded CPS dynamically adjusts the pump's rotational speed based on simulated clinical conditions. Notably, there is no aortic reflux to the ventricle through the VAD during testing. These findings affirm the satisfactory control performance of the embedded CPS in regulating VADs. The study concludes that the embedded CPS effectively addresses the limitations of current VAD control strategies, exhibiting control performance comparable to computer-based systems. However, further experimentation and in vivo studies are necessary to validate and ensure its applicability in real-world scenarios.

PARSECS_RT: A real-time PARSECS-based communication protocol stack for critical sensing applications

The real-time characteristics of modular systems have been a long sought-after goal in many industries including automotive, aeronautics or mobile robotics. Yet scientists and practitioners are still struggling to find widespread implementation solutions that may accommodate diverse inter-modular real-time communication requirements. In an attempt to cover this research gap, the current paper proposes a real-time version of the PARSECS protocol for low-end devices. Our new protocol, coined as PARSECS_RT, was designed according to Open Systems Interconnection Reference Model. It offers a full communication stack from the physical layer to the application layer on top of the SPI interface in order to provide a stable, hard real-time communication platform. PARSECS_RT was evaluated in real and simulated environments providing promising results.

Mechanism for Efficient Media Propagation in Event-Driven Cyber-Physical Systems

Many key applications in Cyber-Physical Systems require the transmission of speech, audio, or video. These scenarios involve the use of traditional Real-Time Communication (RTC) protocols and technologies, which cannot always be used in the context of core networks. This is particularly critical in the context of Event-Driven Architectures (EDAs), where RTC protocols require the use of complex topologies that rely on costly infrastructure. One way to avoid this is by encapsulating all media traffic in EDA protocols. However, this approach does not come without challenges. Specifically, the nature of the transport protocols causes the media to be heavily affected by application layer impairments that render their usage highly impractical. To prevent this from happening, this paper introduces a unified scheme that supports the efficient encapsulation of media traffic in EDA scenarios. This is accomplished through a mechanism that relies on a Machine Learning (ML) model that is exercised in an experimental framework.

Performance Evaluation of WebRTC-Based Video Conferencing: A Comprehensive Analysis

In an ever-evolving technological landscape, addressing the performance challenges of real-time communication protocols is crucial. Real-time communication, facilitated by streaming media protocols, utilizes peer-to-peer or client-server models to enhance Quality of Service (QoS). WebRTC (Web Real-Time Communication) stands as a widely adopted, browser-based, open-source, peer-to-peer protocol, offering real-time media transmission through JavaScript APIs without third-party plugins. This paper presents an in-depth performance evaluation of a WebRTC-based video conferencing system using Socket.io services on a Node.js server. Our research expands on recent studies by introducing a comprehensive set of performance parameters, including Processing delay, CPU Utilization, Latency, Jitter, and Packet Loss, and packet delay. Our findings indicate that WebRTC performs exceptionally well within specific latency thresholds. However, scalability concerns emerge when a large number of clients are introduced, especially in bandwidth-constrained environments.

A Protocol for Reliable Real-Time Wireless Communication of Large Data Samples

In this paper, we present a middleware protocol, that transmits larger-than-a-frame data samples within application real-time and reliability requirements over a lossy wireless channel. The protocol efficiently deploys an intelligent retransmission control that exploits the extended deadline requirements of a sample for frame-level scheduling. The transmission of such samples is placed in the context of the necessary integration of such external sensor data into the decision-making process of an autonomous vehicle. Therefore, we provide parameterization and access rules for communication links in resource-managed scenarios and lay out how to integrate the protocol into the popular DDS middleware. The performance of the parameterized links to satisfy their reliability requirements is studied and compared to error protection protocols in the current software stack. We base the evaluation on an OMNeT++ simulation, whereby an established wireless error model is used. The use case is placed in the context of collaborative sensing in a valet parking environment, where external infrastructure sensor data augments the autonomous vehicle's data processing chain via a lossy wireless link. Thereby, the use case adheres to the underlying safety requirements. Results show that if the protocol's awareness of the application requirements is used for parameterization, guarantees for reliability can be provided that outperform existing solutions.

AN INTERACTION MODEL OF RELAY PROTECTION MEASURING TRANSDUCERS WITH COMPUTING SYSTEMS VIA IIOT TECHNOLOGY

"The object of this research is the interaction model between measuring transducers and computing systems, particularly focusing on its application within the framework of Industrial Internet of Things (IIoT) and Cloud technologies. The imperative driving this study is the increasing demand for precise and efficient data acquisition, protection and processing in various industrial sectors. The research aims to address this need by elucidating an interaction model that optimizes measuring computing systems through IIoT and Cloud technologies. As a result of our research, a comprehensive interaction model that encompasses the entire data flow process was established. This model integrates data acquisition, analytics, real-time communication protocols, and secure data transmission methodologies. It offers a structured framework for acquiring, transmitting, and analyzing data with high accuracy and efficiency. The significance of our results lies in their capacity to resolve critical challenges in data acquisition and processing of the electrical power data, as well as monitoring and protection against electrical faults. These results hold practical value under diverse industrial conditions, including manufacturing, energy production and energy distribution. Keywords: relay protection, open architecture, encryption, data processing, data visualization, internet of things "

Secure and Lightweight Authentication Protocol for Privacy Preserving Communications in Smart City Applications

A smart city is a concept that leverages technology to improve the quality of life for citizens, enhance sustainability, and streamline urban services. The goal of a smart city is to use data and technology to manage resources and assets efficiently, make informed decisions, and create a more livable and thriving city for its residents. Smart cities rely on a range of technologies including the Internet of Things (IoT), Artificial Intelligence (AI), big data analytics, and cloud computing to gather, process, and analyze data from various sources. The aim is to create a city that is more connected, responsive, and sustainable, and that provides its residents with a better quality of life, opportunities, and services. A secure and efficient message communication protocol for sensitive information and real-time communication is critical for the functioning of a smart city environment. The main findings of this paper are to develop a new authentication protocol that meets the specific requirements and constraints of smart city applications. The message communication between smart cities is conducted with the help of a gateway. The challenge in constructing a working, viable infrastructure for a smart city is to provide secure authentication for message communication between the user and gateway node in one network, and the gateway node of one network to the gateway node of the other network. The objective for doing research to develop an authentication protocol that ensures the privacy and security of data transmitted in smart city applications while maintaining a lightweight and efficient design. This paper proposes a secure authentication protocol and key establishment scheme for access to the application in smart cities to make feasible access through the IoT environment. The proposed protocol ensures the mutual authentication between user and gateways, and the security analysis shows that the proposed protocol is effective against energy consumption and have less computational cost. The performance of the proposed method is analyzed and tested using BAN Logic and AVISPA security verification to confirm the authenticity of the security protocol. We do compare with past studies of which our proposed method outperformed.

Adaptive Network Traffic Reduction on the Fly With Programmable Data Planes

Industrial networks rely on standard real-time communication protocols, such as ProfiNet RT. These real-time protocols use cyclic data exchange between IO devices and controllers. Each IO device reports its internal state to the controller at a predefined frequency, even if the state of the device is unchanged. These reports are essential to accurately monitor the health of the devices, but network resources are limited and it is not advisable to overload the network with unnecessary packets. The traffic generated by a single device is insignificant, but in an industrial site with hundreds of such devices, the number of packets to be transmitted adds up. As cloud-based industrial controllers (e.g., cloud-based soft-PLCs) become more prevalent, all generated IO device traffic must be forwarded over the access link to edge computing or private/public cloud infrastructure. Wireless (e.g. 5G radio) transmission of many small packets leads to spectrum efficiency issues and high power consumption. In this paper, we propose an in-network solution to significantly reduce industrial network traffic by cooperating with two P4 programmable network elements deployed on both sides of an access link. Excess traffic is filtered out and new data content is cached at both ends while detecting both link and device failures in real-time. The adaptive mechanism introduced allows the system to automatically optimize its efficiency and performance by dynamically enabling and disabling traffic filtering/caching. Our measurements show that the method can significantly reduce the wireless link load while being seamlessly deployable in existing industrial environments without modifying the protocol, IO devices, and controllers.

MRT-LoRa: A multi-hop real-time communication protocol for industrial IoT applications over LoRa networks

Recent literature proposed MAC protocols running on top of LoRa that are able to offer real-time communications for Industrial Internet of Things (IIoT) applications. However, such solutions work over single-hop star topologies and therefore, to reach a wide coverage through a single hop, they require to configure the LoRa radio parameters in a way that reduces the maximum supported bit rate, thus increasing the message time on air. Consequently, to comply with the maximum duty cycle constraints imposed on LoRa devices by the current regulations, the maximum number of messages that can be sent per hour is also reduced. However, industrial environments typically cover very large areas and require bit rate values in the order of a few thousands of bits per second for LoRa-based networks. To cope with both coverage and bit rate requirements of IIoT, a multi-hop protocol able to provide bounded delays to the real-time flows typical of industrial applications is a better solution than a single-hop approach. For this reason, this paper proposes MRT-LoRa, a multi-hop communication protocol running on top of LoRa that provides support for real-time flows. The MRT-LoRa protocol enables long-range communications while maintaining shorter time on air at each hop, thus lowering the impact on the duty cycle of each node. The paper describes the MRT-LoRa design and configuration, and discusses the performance obtained through OMNeT++ simulations in realistic industrial IoT scenarios.

Session Initiation Protocol Proxy in a Role of a Quality of Service Control Application in Software-Defined Networks

This article deals with quality of service (QoS) in internet protocol (IP) telephony by applying software-defined networking (SDN) tools. The authors develop a new design that deterministically classifies real-time protocol (RTP) streams based on data found in session initiation protocol (SIP) using SIP proxy as a mediator, and the concept making this possible is called SDN. Compared to traditional networks, SDN allows us to approach network configuration differently. SDN networks are programmable through software applications running on top of the SDN controller. One of the technologies that might benefit from this concept is IP telephony, which often needs an additional priority management configuration to ensure consistent quality of its real-time media exchange. Typically, a session protocol for real-time communications is SIP, and as such, its infrastructure may be used to classify the traffic in question and take advantage of the centralized approach of SDN networks to distribute the class information across the switching devices. Different approaches and possible applications are discussed in the conclusion. The contribution of this paper lies in the proposal of SDN-based QoS mechanisms. The entire design of the concept was implemented and validated in a laboratory environment. The results clearly demonstrate the efficiency of the proposed approach.

Expandable Fully Actuated Aerial Vehicle Assembly: Geometric Control Adapted from an Existing Flight Controller and Real-World Prototype Implementation

An assembly composed of multiple aerial vehicles can realize omnidirectional motion with six degrees of freedom. Such an assembly has a heavier payload capacity and better fault tolerance compared with a single aircraft. Thus, such assemblies have the potential to become an ideal platform for manipulation. This paper investigates the controller design and prototype implementation for an expandable aerial vehicle assembly (AVA). The proposed AVA is composed of multiple sub-aircraft connected together via spherical joints at their center of mass. Each sub-aircraft can rotate around the spherical joint. The system dynamics of such an AVA can be separated into a slowly varying system and a fast varying system. The design criteria for a controller for this type of AVA was analyzed based on the similarity between the slowly varying system and a fully actuated rigid aircraft. This can reduce the design procedure for the controller and increase the expandability of the AVA. The stability criteria were carefully analyzed by considering the tracking error of each sub-aircraft. As an example, the controller of the AVA was designed using trajectory linearization control on the manifold, since the configuration space of the aircraft is a non-Euclidean space. A prototype composed of three quadrotors was implemented. The real-time expandable communication protocol among the different sub-aircraft was designed based on the CAN bus. Furthermore, the software and the hardware of the real-world prototype were developed. Both simulation and real-world tests were conducted, which validated the feasibility of the control design and the software implementation for an expandable assembly containing multiple aerial vehicles.

CAN-D: A Modular Four-Step Pipeline for Comprehensively Decoding Controller Area Network Data

Controller area networks (CANs) are a broadcast protocol for real-time communication of critical vehicle subsystems. Original equipment manufacturers of passenger vehicles hold secret their mappings of CAN data to vehicle signals, and these definitions vary according to make, model, and year. Without these mappings, the wealth of real-time vehicle information hidden in the CAN packets is uninterpretable, severely impeding vehicle-related research, including CAN cybersecurity and privacy studies, aftermarket tuning, efficiency and performance monitoring, and fault diagnosis to name a few. Guided by the four-part CAN signal definition, we present CAN-D (CAN-Decoder), a modular, four-step pipeline for identifying each signal's boundaries (start bit and length), endianness (byte ordering), signedness (bit-to-integer encoding), and by leveraging diagnostic standards, augmenting a subset of the extracted signals with meaningful, physical interpretation. En route to CAN-D, we provide a comprehensive review of the CAN signal reverse engineering research. All previous methods ignore endianness and signedness, rendering them incapable of decoding many standard CAN signal definitions. Incorporating endianness grows the search space from 128 to 4.72E21 signal tokenizations and introduces a web of changing dependencies. In response, we formulate, formally analyze, and provide an efficient solution to an optimization problem, allowing identification of the optimal set of signal boundaries and byte orderings. In addition, we provide two novel, state-of-the-art signal boundary classifiers—both of which are superior to previous approaches in precision and recall in three different test scenarios—and the first signedness classification algorithm, which exhibits a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$&gt;$</tex-math></inline-formula> 97% F-score. Overall, CAN-D is the only solution with the potential to extract any CAN signal that is also the state of the art. In evaluation on 10 vehicles of different makes, CAN-D's average <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\ell ^1$</tex-math></inline-formula> error is five times better (81% less) than all previous methods and exhibits lower average error, even when considering only signals that meet prior methods’ assumptions. Finally, CAN-D is implemented in lightweight hardware, allowing for an on-board diagnostic (OBD-II) plugin for real-time in-vehicle CAN decoding.

Optimization of Multi-Intelligent Robot Control System Based on Wireless Communication Network

The robot is a very complex multi-input multioutput nonlinear system. It has time-varying, strong coupling, and nonlinear dynamic characteristics, and its control is very complicated. Due to the inaccuracy of measurement and modeling, coupled with changes in the load and the influence of external disturbances, it is actually impossible to obtain an accurate and complete dynamic model of the robot. We must face the existence of various uncertain factors of the robot. This paper analyzes the real-time communication protocol in the wireless network control system and confirms that the main way to improve the real-time performance of the wireless network control system is to implement the real-time media access control (MAC) protocol. This paper studies robots from the perspective of control and mainly discusses how to use artificial immune algorithms to design robust nonlinear proportion integral derivative (PID) controllers. A nonlinear PID controller is used to replace the classic PID controller. The nonlinear link can be adjusted with the change of the error, so as to achieve the purpose of improving the adaptability and robustness to obtain satisfactory tracking performance. We carried out selective compliance assembly robot arm (SCARA) robot remote control experiment, dual robot following experiment, SCARA and ABB robot collisionless motion planning experiment, and multirobot intelligent collaborative assembly experiment. The experimental results show that the C/S mode remote control system has good practicability and can complete remote tasks; the P2P communication system has good information transmission effects and can realize real-time information sharing between robots; the collision-free motion planning algorithm enables the dual robots to complete obstacle avoidance tasks well in complex operating environments; the functional modules of the system can closely cooperate to complete the tasks in coordination, and the multirobot system has a certain degree of intelligence.

A Cyber Collaborative Protocol for Real-Time Communication and Control in Human-Robot-Sensor Work

Real-time communication and control are essential parts of the Cyber Physical System (CPS) to optimize effective performance and reliability. To gain a sustainable competitive advantage with Automation 5.0, as needed in Work-of-the-Future, this article addresses the concept of real-time communication and control in the case of an agricultural work setting, along with a newly designed Cyber Collaborative Protocol, called CCP-RTC2. The developed protocol aims to minimize information delay and maximize JIN (Just In Need) information sharing, to enable collaborative decisions among system agents. Two experiments are conducted to compare the designed protocol’s performance in agricultural CPS against the current non-CPS practice. The results demonstrate that the CCP-RTC2 is superior compared with current practice in terms of information sharing in a normal operation scenario. When the system obtains an unplanned request, the CCP-RTC2 can integrate such a request to the original work plan while minimizing the system’s objective function (lower is better). Hence, the system has relatively smaller information delays, as well as better timely information shared with system agents that need it.

Estimating PQoS of Video Conferencing on Wi-Fi Networks Using Machine Learning

Video conferencing services based on web real-time communication (WebRTC) protocol are growing in popularity among Internet users as multi-platform solutions enabling interactive communication from anywhere, especially during this pandemic era. Meanwhile, Internet service providers (ISPs) have deployed fiber links and customer premises equipment that operate according to recent 802.11ac/ax standards and promise users the ability to establish uninterrupted video conferencing calls with ultra-high-definition video and audio quality. However, the best-effort nature of 802.11 networks and the high variability of wireless medium conditions hinder users experiencing uninterrupted high-quality video conferencing. This paper presents a novel approach to estimate the perceived quality of service (PQoS) of video conferencing using only 802.11-specific network performance parameters collected from Wi-Fi access points (APs) on customer premises. This study produced datasets comprising 802.11-specific network performance parameters collected from off-the-shelf Wi-Fi APs operating at 802.11g/n/ac/ax standards on both 2.4 and 5 GHz frequency bands to train machine learning algorithms. In this way, we achieved classification accuracies of 92–98% in estimating the level of PQoS of video conferencing services on various Wi-Fi networks. To efficiently troubleshoot wireless issues, we further analyzed the machine learning model to correlate features in the model with the root cause of quality degradation. Thus, ISPs can utilize the approach presented in this study to provide predictable and measurable wireless quality by implementing a non-intrusive quality monitoring approach in the form of edge computing that preserves customers’ privacy while reducing the operational costs of monitoring and data analytics.

Performance Analysis of WebRTC and SIP-based Audio and Video Communication Systems

Video and audio communications have become an integral part of all spheres of life. Two commonly used real-time communication protocols for IP-based video and audio communications are the session initiation protocol (SIP) and web real-time communications (WebRTC). These two protocols have been widely used in softphone and video conferencing applications. The main aim of this paper is to make a comparative analysis of the performance of client server applications for video and audio communications developed by both SIP and WebRTC. The SIP system comprises of a desktop client developed in C#, a mobile client developed in Android studio and a FreeSwitch server. For the WebRTC application, the client was developed in JavaScript and the server in Node.js. The WebRTC application also included a speech translation API for real-time speech translation and employed two different codecs namely VP8 and VP9 via a modification of the Session Description Protocol (SDP) header. Results showed that WebRTC peer-to-peer audio communication provides a much lower quality in terms of SSNR than the SIP audio calls. However, for video communications, WebRTC provides better quality in terms of PSNR than SIP. The performance of the WebRTC application was also evaluated with the different codecs in terms of PSNR as well as the impact of the real-time speech translation delay.

An Ensemble of Ensembles Approach to Author Attribution for Internet Relay Chat Forensics

With the advances in Internet technologies and services, social media has been gained extreme popularity, especially because these technologies provide potential anonymity, which in turn harbors hacker discussion forums, underground markets, dark web, and so on. Internet relay chat (IRC) is a real-time communication protocol actively used by cybercriminals for hacking, cracking, and carding. Hence, it is particularly urgent to identify the authors of threat messages and malicious activities in IRC. Unfortunately, author identification studies in IRC remain as an underexplored area. In this research, we perform novel IRC text feature extraction methods and propose the first author attribution version of the deep forest (DF) model that is an ensemble of ensembles that utilizes the fusion of ensemble learning techniques. Our approach is supported by autonomic IRC monitoring. Experiments show that our approach is highly effective for author attribution and attains high accuracy even when the number of candidates is large while training data is limited.

An analysis and simulation tool of real-time communications in on-chip networks

This paper presents Real-Time Network-on-chip-based architecture Analysis and Simulation tool (ReTiNAS), with a special focus on real-time communications. It allows fast and precise exploration of real-time design choices onto NoC architectures. ReTiNAS is an event-based simulator written in Python. It implements different real-time communication protocols and tracks the communications within the NoC at cycle level. Its modularity allows activating and deactivating different NoC components and easily extending the implemented protocols for more customized simulations and analysis. Further, we use ReTiNAS to perform a comparative study of analysis and simulation for different communication protocols using a wide set of synthetic experiments.

A Telepresence Wheelchair with 360-Degree Vision Using WebRTC

This paper presents an innovative approach to develop an advanced 360-degree vision telepresence wheelchair for healthcare applications. The study aims at improving a wide field of view surrounding the wheelchair to provide safe wheelchair navigation and efficient assistance for wheelchair users. A dual-fisheye camera is mounted in front of the wheelchair to capture images which can be then streamed over the Internet. A web real-time communication (WebRTC) protocol was implemented to provide efficient video and data streaming. An estimation model based on artificial neural networks was developed to evaluate the quality of experience (QoE) of video streaming. Experimental results confirmed that the proposed telepresence wheelchair system was able to stream a 360-degree video surrounding the wheelchair smoothly in real-time. The average streaming rate of the entire 360-degree video was 25.83 frames per second (fps), and the average peak signal to noise ratio (PSNR) was 29.06 dB. Simulation results of the proposed QoE estimation scheme provided a prediction accuracy of 94%. Furthermore, the results showed that the designed system could be controlled remotely via the wireless Internet to follow the desired path with high accuracy. The overall results demonstrate the effectiveness of our proposed approach for the 360-degree vision telepresence wheelchair for assistive technology applications.

Outdoor cooperative flight using decentralized consensus algorithm and a guaranteed real-time communication protocol

This paper describes the implementation of a decentralized consensus law with theoretically provable convergence properties on a multi-agent testbed comprising of quadrotors. It is shown that for small roll and pitch angles and well-tuned control loops, the quadrotor dynamics can be approximated as a pair of double integrators. Several experiments are carried out in an outdoor environment for validation of the consensus law which is based on double integrator dynamics. For any arbitrary initial positions of the quadrotors, the consensus law is able to drive them to an autonomously decided common point, given that the communication graph is connected at each instant of time. The resulting experimental trajectories and the consensus point matches with theoretical predictions. For guaranteeing real-time reliability required for such coordinated motion, a novel synchronized, time-slotted, scalable and fully airborne communication protocol is proposed. The protocol avoids data collisions and ensures real-time, reliable communication between agents. It can also address changing communication graph topologies, temporary link-breaks and additions. Using this underlying protocol, the quadrotors attain consensus for static and dynamic communication graphs. Experiments to observe the effect of communication rate on consensus performance are also conducted.