MediaSync: Handbook on Multimedia Synchronization

This book provides an approachable overview of the most recent advances in the fascinating field of media synchronization (mediasync), gathering contributions from the most representative and influential experts. Understanding the challenges of this field in the current multi-sensory, multi-device, and multi-protocol world is not an easy task. The book revisits the foundations of mediasync, including theoretical frameworks and models, highlights ongoing research efforts, like hybrid broadband broadcast (HBB) delivery and users' perception modeling (i.e., Quality of Experience or QoE), and paves the way for the future (e.g., towards the deployment of multi-sensory and ultra-realistic experiences). Although many advances around mediasync have been devised and deployed, this area of research is getting renewed attention to overcome remaining challenges in the next-generation (heterogeneous and ubiquitous) media ecosystem. Given the significant advances in this research area, its current relevance and the multiple disciplines it involves, the availability of a reference book on mediasync becomes necessary. This book fills the gap in this context. In particular, it addresses key aspects and reviews the most relevant contributions within the mediasync research space, from different perspectives. Mediasync: Handbook on Multimedia Synchronization is the perfect companion for scholars and practitioners that want to acquire strong knowledge about this research area, and also approach the challenges behind ensuring the best mediated experiences, by providing the adequate synchronization between the media elements that constitute these experiences

An Exploratory Analysis Of A Time Synchronization Protocol For UAS

This dissertation provides a numerical analysis of a Receiver Only Synchronization (ROS) protocol which is proposed for use by Unmanned Aircraft Systems (UAS) in Beyond Visual Line of Sight (BVLOS) operations. The use of ROS protocols could reinforce current technologies that enable transmission over 5G cell networks, decreasing latency issues and enabling the incorporation of an increased number of UAS to the network, without loss of accuracy. A minimum squared error (MSE)-based accuracy of clock offset and clock skew estimations was obtained using the number of iterations and number of observations as independent parameters. Although the model converged after only four iterations, the number of observations needed was considerably large, of no less than about 250. The noise, introduced in the system through the first residual, the correlation parameter and the disturbance terms, was assumed to be autocorrelated. Previous studies suggested that correlated noise might be typical in multipath scenarios, or in case of damaged antennas. Four noise distributions: gaussian, exponential, gamma and Weibull were considered. Each of them is adapted to different noise sources in the OSI model. Dispersion of results in the first case, the only case with zero mean, was checked against the Cramér-Rao Bound (CRB) limit. Results confirmed that the scheme proposed was fully efficient. Moreover, results with the other three cases were less promising, thus demonstrating that only zero mean distributions could deliver good results. This fact would limit the proposed scheme application in multipath scenarios, where echoes of previous signals may reach the receiver at delayed times. In the second part, a wake/sleep scheme was imposed on the model, concluding that for wake/sleep ratios below 92/08 results were not accurate at p=.05 level. The study also evaluated the impact of noise levels in the time domain and showed that above -2dB in time a substantial contribution of error terms disturbed the initial estimations significantly. The tests were performed in Matlab®. Based on the results, three venues confirming the assumptions made were proposed for future work. Some final reflections on the use of 5G in aviation brought the present dissertation to a close

A SECURITY-CENTRIC APPLICATION OF PRECISION TIME PROTOCOL WITHIN ICS/SCADA SYSTEMS

Industrial Control System and Supervisory Control and Data Acquisition (ICS/SCADA) systems are key pieces of larger infrastructure that are responsible for safely operating transportation, industrial operations, and military equipment, among many other applications. ICS/SCADA systems rely on precise timing and clear communication paths between control elements and sensors. Because ICS/SCADA system designs place a premium on timeliness and availability of data, security ended up as an afterthought, stacked on top of existing (insecure) protocols. As precise timing is already resident and inherent in most ICS/SCADA systems, a unique opportunity is presented to leverage existing technology to potentially enhance the security of these systems. This research seeks to evaluate the utility of timing as a mechanism to mitigate certain types of malicious cyber-based operations such as a man-on-the-side (MotS) attack. By building a functioning ICS/SCADA system and communication loop that incorporates precise timing strategies in the reporting and control loop, specifically the precision time protocol (PTP), it was shown that certain kinds of MotS attacks can be mitigated by leveraging precise timing.Navy Cyber Warfare Development Group, Suitland, MDLieutenant, United States NavyApproved for public release. Distribution is unlimited

Design, Development and Assessment of Control Schemes for IDMS in a Standardized RTCP-based Solution

[EN] Currently, several media sharing applications that allow social interactions between distributed users are gaining momentum. In these networked scenarios, synchronized playout between the involved participants must be provided to enable truly interactive and coherent shared media experiences. This research topic is known as Inter-Destination Media Synchronization (IDMS). This paper presents the design and development of an advanced IDMS solution, which is based on extending the capabilities of RTP/RTCP standard protocols. Particularly, novel RTCP extensions, in combination with several control algorithms and adjustment techniques, have been specified to enable an adaptive, highly accurate and standard compliant IDMS solution. Moreover, as different control or architectural schemes for IDMS exist, and each one is best suited for specific use cases, the IDMS solution has been extended to be able to adopt each one of them. Simulation results prove the satisfactory responsiveness of our IDMS solution in a small scale scenario, as well as its consistent behavior, when using each one of the deployed architectural schemes.This work has been financed, partially, by Universitat Politecnica de Valencia (UPV), under its R&D Support Program in PAID-01-10. TNO's work has been partially funded by European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. ICT-2011-8-318343 (STEER Project). CWI's work has been partially funded by the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. ICT-2011-7-287723 (REVERIE Project).Montagud Aguar, M.; Boronat Segui, F.; Stokking, H.; Cesar, P. (2014). Design, Development and Assessment of Control Schemes for IDMS in a Standardized RTCP-based Solution. Computer Networks. 70:240-259. https://doi.org/10.1016/j.comnet.2014.06.004S2402597

Analysis on Applications of Network Technology in Subaqueous Sensor System

For the quick development of wireless sensor network and more attention for marine cause from every country, study of the application of network technology in subaqueous sensor system has been the hot topic. The subaqueous sensors network is mainly made up of a great number of sensor nodes and few workstations. These nodes can obtain important information such as the salinity, water temperature and flow rate. In order to meet the requirements of marine exploration and detection, the equipment system has become more and more huge, leading the reliability reduced in some way. And this problem can be solved with the help of the new network technology like optical devices, communications protocol. In this paper, we take the significance, characteristics and problems of subaqueous sensor networks as the outset, then discuss how to ensure the reliability and usability and the application of optical devices in optical network

Design and Implementation of a Scalable Hardware Platform for High Speed Optical Tracking

Optical tracking has been an important subject of research since several decades. The utilization of optical tracking systems can be found in a wide range of areas, including military, medicine, industry, entertainment, etc. In this thesis a complete hardware platform that targets high-speed optical tracking applications is presented. The implemented hardware system contains three main components: a high-speed camera which is equipped with a 1.3M pixel image sensor capable of operating at 500 frames per second, a CameraLink grabber which is able to interface three cameras, and an FPGA+Dual-DSP based image processing platform. The hardware system is designed using a modular approach. The flexible architecture enables to construct a scalable optical tracking system, which allows a large number of cameras to be used in the tracking environment. One of the greatest challenges in a multi-camera based optical tracking system is the huge amounts of image data that must be processed in real-time. In this thesis, the study on FPGA based high-speed image processing is performed. The FPGA implementation for a number of image processing operators is described. How to exploit different levels of parallelisms in the algorithm to achieve high processing throughput is explained in detail. This thesis also presents a new single-pass blob analysis algorithm. With an optimized FPGA implementation, the geometrical features of a large number of blobs can be calculated in real-time. At the end of this thesis, a prototype design which integrates all the implemented hardware and software modules is demonstrated to prove the usability of the proposed optical tracking system

Digital Signal Processor Based Real-Time Phased Array Radar Backend System and Optimization Algorithms

This dissertation presents an implementation of multifunctional large-scale phased array radar based on the scalable DSP platform. The challenge of building large-scale phased array radar backend is how to address the compute-intensive operations and high data throughput requirement in both front-end and backend in real-time. In most of the applications, FPGA or VLSI hardware are typically used to solve those difficulties. However, with the help of the fast development of IC industry, using a parallel set of high-performing programmable chips can be an alternative. We present a hybrid high-performance backend system by using DSP as the core computing device and MTCA as the system frame. Thus, the mapping techniques for the front and backend signal processing algorithm based on DSP are discussed in depth. Beside high-efficiency computing device, the system architecture would be a major factor influencing the reliability and performance of the backend system. The reliability requires the system must incorporate the redundancy both in hardware and software. In this dissertation, we propose a parallel modular system based on MTCA chassis, which can be reliable, scalable, and fault-tolerant. Finally, we present an example of high performance phased array radar backend, in which there is the number of 220 DSPs, achieving 7000 GFLOPS calculation from 768 channels. This example shows the potential of using the combination of DSP and MTCA as the computing platform for the future multi-functional large-scale phased array radar

On-board B-ISDN fast packet switching architectures. Phase 2: Development. Proof-of-concept architecture definition report

For the next-generation packet switched communications satellite system with onboard processing and spot-beam operation, a reliable onboard fast packet switch is essential to route packets from different uplink beams to different downlink beams. The rapid emergence of point-to-point services such as video distribution, and the large demand for video conference, distributed data processing, and network management makes the multicast function essential to a fast packet switch (FPS). The satellite's inherent broadcast features gives the satellite network an advantage over the terrestrial network in providing multicast services. This report evaluates alternate multicast FPS architectures for onboard baseband switching applications and selects a candidate for subsequent breadboard development. Architecture evaluation and selection will be based on the study performed in phase 1, 'Onboard B-ISDN Fast Packet Switching Architectures', and other switch architectures which have become commercially available as large scale integration (LSI) devices

Modular and Safe Event-Driven Programming

Asynchronous event-driven systems are ubiquitous across domains such as device drivers, distributed systems, and robotics. These systems are notoriously hard to get right as the programmer needs to reason about numerous control paths resulting from the complex interleaving of events (or messages) and failures. Unsurprisingly, it is easy to introduce subtle errors while attempting to fill in gaps between high-level system specifications and their concrete implementations.This dissertation proposes new methods for programming safe event-driven asynchronous systems.In the first part of the thesis, we present ModP, a modular programming framework for compositional programming and testing of event-driven asynchronous systems.The ModP module system supports a novel theory of compositional refinement for assume-guarantee reasoning of dynamic event-driven asynchronous systems. We build a complex distributed systems software stack using ModP.Our results demonstrate that compositional reasoning can help scale model-checking (both explicit and symbolic) to large distributed systems.ModP is transforming the way asynchronous software is built at Microsoft and Amazon Web Services (AWS). Microsoft uses ModP for implementing safe device drivers and other software in the Windows kernel.AWS uses ModP for compositional model checking of complex distributed systems. While ModP simplifies analysis of such systems, the state space of industrial-scale systems remains extremely large.In the second part of this thesis, we present scalable verification and systematic testing approaches to further mitigate this state-space explosion problem.First, we introduce the concept of a delaying explorer to perform prioritized exploration of the behaviors of an asynchronous reactive program. A delaying explorer stratifies the search space using a custom strategy (tailored towards finding bugs faster), and a delay operation that allows deviation from that strategy. We show that prioritized search with a delaying explorer performs significantly better than existing approaches for finding bugs in asynchronous programs.Next, we consider the challenge of verifying time-synchronized systems; these are almost-synchronous systems as they are neither completely asynchronous nor synchronous.We introduce approximate synchrony, a sound and tunable abstraction for verification of almost-synchronous systems. We show how approximate synchrony can be used for verification of both time-synchronization protocols and applications running on top of them.Moreover, we show how approximate synchrony also provides a useful strategy to guide state-space exploration during model-checking.Using approximate synchrony and implementing it as a delaying explorer, we were able to verify the correctness of the IEEE 1588 distributed time-synchronization protocol and, in the process, uncovered a bug in the protocol that was well appreciated by the standards committee.In the final part of this thesis, we consider the challenge of programming a special class of event-driven asynchronous systems -- safe autonomous robotics systems.Our approach towards achieving assured autonomy for robotics systems consists of two parts: (1) a high-level programming language for implementing and validating the reactive robotics software stack; and (2) an integrated runtime assurance system to ensure that the assumptions used during design-time validation of the high-level software hold at runtime.Combining high-level programming language and model-checking with runtime assurance helps us bridge the gap between design-time software validation that makes assumptions about the untrusted components (e.g., low-level controllers), and the physical world, and the actual execution of the software on a real robotic platform in the physical world. We implemented our approach as DRONA, a programming framework for building safe robotics systems.We used DRONA for building a distributed mobile robotics system and deployed it on real drone platforms. Our results demonstrate that DRONA (with the runtime-assurance capabilities) enables programmers to build an autonomous robotics software stack with formal safety guarantees.To summarize, this thesis contributes new theory and tools to the areas of programming languages, verification, systematic testing, and runtime assurance for programming safe asynchronous event-driven across the domains of fault-tolerant distributed systems and safe autonomous robotics systems