3,523 research outputs found

    Securing Real-Time Internet-of-Things

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    Modern embedded and cyber-physical systems are ubiquitous. A large number of critical cyber-physical systems have real-time requirements (e.g., avionics, automobiles, power grids, manufacturing systems, industrial control systems, etc.). Recent developments and new functionality requires real-time embedded devices to be connected to the Internet. This gives rise to the real-time Internet-of-things (RT-IoT) that promises a better user experience through stronger connectivity and efficient use of next-generation embedded devices. However RT- IoT are also increasingly becoming targets for cyber-attacks which is exacerbated by this increased connectivity. This paper gives an introduction to RT-IoT systems, an outlook of current approaches and possible research challenges towards secure RT- IoT frameworks

    A Real-Time Communication Framework for Wireless Sensor Networks

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    Recent advances in miniaturization and low power design have led to a flurry of activity in wireless sensor networks. Sensor networks have different constraints than traditional wired networks. A wireless sensor network is a special network with large numbers of nodes equipped with embedded processors, sensors, and radios. These nodes collaborate to accomplish a common task such as environment monitoring or asset tracking. In many applications, sensor nodes will be deployed in an ad-hoc fashion without careful planning. They must organize themselves to form a multihop, wireless communication network. In sensor network environments, much research has been conducted in areas such as power consumption, self-organisation techniques, routing between the sensors, and the communication between the sensor and the sink. On the other hand, real-time communication with the Quality of Service (QoS) concept in wireless sensor networks is still an open research field. Most protocols either ignore real time or simply attempt to process as fast as possible and hope that this speed is sufficient to meet the deadline. However, the introduction of real-time communication has created additional challenges in this area. The sensor node spends most of its life routing packets from one node to another until the packet reaches the sink; therefore, the node functions as a small router most of the time. Since sensor networks deal with time-critical applications, it is often necessary for communication to meet real time constraints. However, research that deals with providing QoS guarantees for real-time traffic in sensor networks is still in its infancy.This thesis presents a real-time communication framework to provide quality of service in sensor networks environments. The proposed framework consists of four components: First, present an analytical model for implementing Priority Queuing (PQ) in a sensor node to calculate the queuing delay. The exact packet delay for corresponding classes is calculated. Further, the analytical results are validated through an extensive simulation study. Second, report on a novel analytical model based on a limited service polling discipline. The model is based on an M/D/1 queuing system (a special class of M/G/1 queuing systems), which takes into account two different classes of traffic in a sensor node. The proposed model implements two queues in a sensor node that are served in a round robin fashion. The exact queuing delay in a sensor node for corresponding classes is calculated. Then, the analytical results are validated through an extensive simulation study. Third, exhibit a novel packet delivery mechanism, namely the Multiple Level Stateless Protocol (MLSP), as a real-time protocol for sensor networks to guarantee the traffic in wireless sensor networks. MLSP improves the packet loss rate and the handling of holes in sensor network much better than its counterpart, MMSPEED. It also introduces the k-limited polling model for the first time. In addition, the whole sending packets dropped significantly compared to MMSPEED, which it leads to decrease the consumption power. Fourth, explain a new framework for moving data from the sink to the user, at a low cost and low power, using the Universal Mobile Telecommunication System (UMTS), which is standard for the Third Generation Mobile System (3G). The integration of sensor networks with the 3G mobile network infrastructure will reduce the cost of building new infrastructures and enable the large-scale deployment of sensor network

    Project DIANA - Converging and Integrating IP and ATM for real-time applications

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    The evolution of IP and ATM share some common drivers. Both of them are addressing efficient network resource utilisation. In order to evaluate the options and combinations offered by these technologies the DIANA project is looking into the areas where ATM and IP both overlap and complete each other, that is QoS interworking between ATM and IP. This is achieved by investigating RSVP-over-ATM approach. This solution is compared with two IP level approaches: Differentiated Services and Scalable Resource Reservation Protocol (SRP)

    Integrating security into real-time cyber-physical systems

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    Cyber-physical systems (CPS) such as automobiles, power plants, avionics systems, unmanned vehicles, medical devices, manufacturing and home automation systems have distinct cyber and physical components that must work cohesively with each other to ensure correct operation. Many cyber-physical applications have “real-time” constraints, i.e., they must function correctly within predetermined time scales. A failure to protect these systems could result in significant harm to humans, the system or even the environment. While traditionally such systems were isolated from external accesses and used proprietary components and protocols, modern CPS use off-the-shelf components and are increasingly interconnected, often via networks such as the Internet. As a result, they are exposed to additional attack surfaces and have become increasingly vulnerable to cyber attacks. Enhancing security for real-time CPS, however, is not an easy task due to limited resource availability (e.g., processing power, memory, storage, energy) and stringent timing/safety requirements. Security monitoring techniques for cyber-physical platforms (a) must execute with existing real-time tasks, (b) operate without impacting the timing and safety constraints of the control logic and (c) have to be designed and executed in a way that an adversary cannot easily evade it. The objective of my research is to increase security posture of embedded real-time CPS by integrating monitoring/detection techniques that defeat cyber attacks without violating timing/safety constraints of existing tasks. My dissertation work explores the real-time security domain and shows that by employing a combination of multiple scheduling/analysis techniques and interactions between hardware/software-based security extensions, it becomes feasible to integrate security monitoring mechanisms in real-time CPS without compromising timing/safety requirements of existing tasks. In this research, I (a) develop techniques to raise the responsiveness of security monitoring tasks by increasing their frequency of execution, (b) design a hardware-supported framework to prevent falsification of actuation commands — i.e., commands that control the state of the physical system and (c) propose metrics to trade-off security with real-time guarantees. The solutions presented in this dissertation require minimal changes to system components/parameters and thus compatible for legacy systems. My proposed frameworks and results are evaluated through both, simulations and experiments on real off-the-shelf cyber-physical platforms. The development of analysis techniques and design frameworks proposed in this dissertation will inherently make such systems more secure and hence, safer. I believe my dissertation work will bring researchers and system engineers one step closer to understand how to integrate two seemingly diverse yet important fields — real-time CPS and cyber-security — while gaining a better understanding of both areas

    Real-Time Guarantees For Wireless Networked Sensing And Control

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    Wireless networks are increasingly being explored for mission-critical sensing and control in emerging domains such as connected and automated vehicles, Industrial 4.0, and smart city. In wireless networked sensing and control (WSC) systems, reliable and real- time delivery of sensed data plays a crucial role for the control decision since out-of-date information will often be irrelevant and even leads to negative effects to the system. Since WSC differs dramatically from the traditional real-time (RT) systems due to its wireless nature, new design objective and perspective are necessary to achieve real-time guarantees. First, we proposed Optimal Node Activation Multiple Access (ONAMA) scheduling protocol that activates as many nodes as possible while ensuring transmission reliability (in terms of packets delivery ratio). We implemented and tested ONAMA on two testbeds both with 120+ sensor nodes. Second, we proposed algorithms to address the problem of clustering heterogeneous reliability requirements into a limit set of service levels. Our solutions are optimal, and they also provide guaranteed reliability, which is critical for wireless sensing and control. Third, we proposed a probabilistic real-time wireless communication framework that effectively integrates real-time scheduling theory with wireless communication. The per- packet probabilistic real-time QoS was formally modeled. By R3 mapping, the upper-layer requirement and the lower-layer link reliability are translated into the number of trans- mission opportunities needed. By optimal real-time communication scheduling as well as admission test and traffic period optimization, the system utilization is maximized while the schedulability is maintained. Finally, we further investigated the problem of how to minimize delay variation (i.e., jitter) while ensuring that packets are delivered by their deadlines

    Modelling the Integrated QoS for Wireless Sensor Networks with Heterogeneous Data Traffic

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    The future of Internet of Things (IoT) is envisaged to consist of a high amount of wireless resource-constrained devices connected to the Internet. Moreover, a lot of novel real-world services offered by IoT devices are realized by wireless sensor networks (WSNs). Integrating WSN to the Internet has therefore brought forward the requirements of an end-to-end quality of service (QoS) guarantee. In this paper, the QoS requirements for the WSN-Internet integration are investigated by first distinguishing the Internet QoS from the WSN QoS. Next, this study emphasizes on WSN applications that involve traffic with different levels of importance, thus the way realtime traffic and delay-tolerant traffic are handled to guarantee QoS in the network is studied. Additionally, an overview of the integration strategies is given, and the delay-tolerant network (DTN) gateway, being one of the desirable approaches for integrating WSNs to the Internet, is discussed. Next, the implementation of the service model is presented, by considering both traffic prioritization and service differentiation. Based on the simulation results in OPNET Modeler, it is observed that real-time traffic achieve low bound delay while delay-tolerant traffic experience a lower packet dropped, hence indicating that the needs of real-time and delay-tolerant traffic can be better met by treating both packet types differently. Furthermore, a vehicular network is used as an example case to describe the applicability of the framework in a real IoT application environment, followed by a discussion on the future work of this research

    Large-Scale Measurement of Real-Time Communication on the Web

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    Web Real-Time Communication (WebRTC) is getting wide adoptions across the browsers (Chrome, Firefox, Opera, etc.) and platforms (PC, Android, iOS). It enables application developers to add real-time communications features (text chat, audio/video calls) to web applications using W3C standard JavaScript APIs, and the end users can enjoy real-time multimedia communication experience from the browser without the complication of installing special applications or browser plug-ins. As WebRTC based applications are getting deployed on the Internet by thousands of companies across the globe, it is very important to understand the quality of the real-time communication services provided by these applications. Important performance metrics to be considered include: whether the communication session was properly setup, what are the network delays, packet loss rate, throughput, etc. At Callstats.io, we provide a solution to address the above concerns. By integrating an JavaScript API into WebRTC applications, Callstats.io helps application providers to measure the Quality of Experience (QoE) related metrics on the end user side. This thesis illustrates how this WebRTC performance measurement system is designed and built and we show some statistics derived from the collected data to give some insight into the performance of today’s WebRTC based real-time communication services. According to our measurement, real-time communication over the Internet are generally performing well in terms of latency and loss. The throughput are good for about 30% of the communication sessions

    Industrial Energy Monitoring System based on the Internet of Things (IoT)

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    Energy monitoring system has long been utilized for basic functionalities such as process scheduling and billing purposes in the industrial scenario. However the use of energy monitoring for improving energy efficiency and the monitoring of degradation in power quality parameters that provides important insights into process degradation and fault diagnosis as long been ignored due to lack of ability of the current energy monitoring systems to acquire and process both energy and power quality data in real-time. The advent of technologies such as the Internet of Things (IoT), Cloud computing and Big Data has made real time acquisition and analysis of data possible. This paper discusses on use of these technologies for developing an integrated real-time power monitoring system and its possible application in fault cause-effect diagnosis. This project focusses on the technologies that would enable the development of the an real-time energy monitoring system and its implementation developing an development of the an real-time energy monitoring syste

    On the use of code mobility mechanisms in real-time systems

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    Applications with soft real-time requirements can benefit from code mobility mechanisms, as long as those mechanisms support the timing and Quality of Service requirements of applications. In this paper, a generic model for code mobility mechanisms is presented. The proposed model gives system designers the necessary tools to perform a statistical timing analysis on the execution of the mobility mechanisms that can be used to determine the impact of code mobility in distributed real-time applications
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