In Intelligent Transport Systems (ITS), the unavailable Road Side Unit (RSU) becomes an increasing serious safety-related problem because of its important role in ITS. However, there is no existing method to solve this problem effectively and stably nowadays. To solve the unavailable RSU problem, a novel 2-tier integrated communication system is proposed in this thesis to address the issue of unavailable RSU in ITS. Compared to some other solutions proposed in the previous research works, which mostly focus on improving the system performance by adjusting parameters of vehicular ad-hoc network among vehicles, the proposed 2-tier communication network, called ITS-LEO Integrated System (ILIS), is composed of conventional ITS system and Low Earth Orbit (LEO) mobile satellite system (MSS), where the LEO MSS is utilized as the complementary network when the RSU is unavailable. Since the LEO MSS primary message will get affected when overflowing messages from ITS to LEO MSS, we prioritize LEO MSS primary message over the overflowed message to minimize the effect, which is based on that the emergency message (EMsg) is given higher priority over routine message (RMsg) to get access to the channel in ITS. To optimize the utility of network resource, two different overflowing mechanisms are proposed in ILIS to improve system efficiency under different traffic density. Furthermore, we propose a bandwidth reservation protection mechanism for ILIS to increase the ITS network performance. A real-time simulation program in C++ is developed to evaluate the performance of ILIS in terms of Packet Loss Rate (PLR) and Delay, and simulation results show that adding LEO MSS as a complementary network to ITS is an effective way to solve the problem of an unavailable RSU.

Since gateways are usually used to integrate the Internet and MANET (Mobile Ad Hoc Network), the gateway discovery approaches is important for mobile nodes in MANET to obtain the route to gateways. The hybrid gateway discovery approach can be configured through adjustment of the single parameter, the TTL (Time-to-live) of the advertisement. This thesis aims to develop an adaptive gateway discovery algorithm to adjust the TTL of advertisement by estimating the control overhead and then effectively adjusts the generation of control overhead in the integrated network. Through the simulation, we demonstrate that this adaptive gateway discovery algorithm can adjust the appropriate TTL of advertisement in different number of mobile nodes which desire to access Internet.

There is an ongoing evolution of technology towards network convergence and ubiquitous information society in which users have broadband access to information resources and services anywhere, anytime. To realize this vision, a communication infrastructure has to be able to support a core backbone network delivering ultra-high capacity data services, a ubiquitous broadband wireless for last-mile access, and a control/management plane providing intelligent control to the infrastructure. Desirable characteristics of the infrastructure include insertion of future technology, intelligent spectrum management, cost-efficient upgradeability, flexible scalability, and cognitive networking capabilities. Unfortunately, present electronic technology alone is incapable of meeting these requirements.This dissertation describes the initial research into the realization of such an architecture that comprises of three crucial frameworks: 1) photonic-based; 2) dynamic chain processing; 3) and physical layer awareness. Due to the superior signal transport properties of optics, an underlying photonic data layer is able to provide the architecture with much wider bandwidth, greater RF-frequency-scalability, and higher operating RF-frequency. Photonics also enables diverse technologies to be integrated into a seamless communications platform. Dynamic processing chain framework provides the flexibility and future-proof capability via reconfigurability and componentization. Physical-layer-awareness offers support for automated adaptation and intelligent configuration of the data plane in response to the dynamic conditions of the physical layer. Crucial functional blocks in this awareness are: efficient estimation of physical impairments of the components and links; an effective dynamic impairment monitoring mechanism; and proficient adaptation to either maximize or optimize performance.Though the architecture encompasses both optical transport network (OTN) and photonic radio, this dissertation focuses more on the OTN. Central themes of OTN in this dissertation include relating Q-factor with various optical impairments from the perspective of an end-to-end optical path, and extending physical layer awareness with impairment routing. One of the key findings advocates that filtering is a serious limitation to bit-rate independence, protocol independence and network scalability promised by transparent network.

This thesis describes a possible integrated terrestrial-satellite network system for disaster recovery and response. The motivation of this thesis was based on the adjacent spectrum allocations between the Virginia Tech terrestrial Local Multiple Distribution Service (LMDS) system and a Ka-band satellite system, and potentially being able to provide as an additional Ka-band satellite network backbone to the Virginia Tech terrestrial LMDS system for better and faster communications deployments. The Spaceway satellite system's design parameters were adopted typically for a Ka-band satellite system. The LMDS system was assumed to use IEEE 802.16 standard protocols although it currently uses its own proprietary protocols. Four possible topologies integrating both terrestrial and satellite network were investigated. The study showed that the task was more problematic and complicated than anticipated due to incompatible network protocols, limitations of available hardware components, the high path loss at Ka-band, and the high cost of the equipment, although the adjacent frequency bands do suggest a possible integrated network. In this thesis, the final selected topology was proposed and designed. The technical characteristics of the earth station used for coupling both terrestrial and satellite networks were determined by a link budget analysis and a consideration of network implementations. The reflector antenna used by the earth station was designed. In addition, other system design concerns and engineering tradeoffs, including adjacent satellite interference, rain attenuation, antenna pointing error, noise temperature, and modulation and multiple access selection, were addressed. / Master of Science

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada

ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / As the integrated Network Enhanced Telemetry (iNET) program prepares for developmental flights tests, refinements are being made to the Radio Access Network Standard that ensures interoperability of networked radio components. One key aspect of this interoperability is the definition of Telemetry Network System (TmNS) RF Data Link Layer functionality for conducting efficient communications between radios in a TDMA (Time Division Multiple Access) channel sharing scheme. This paper examines the overall structure of the TmNS RF Data Link Layer and provides an overview of its operation. Specific topics include Medium Access Control (MAC) scheduling and framing in the context of a burst-oriented TDMA structure, link layer encryption, the priority-enabled Automatic Repeat reQuest (ARQ) protocol, high-level network packet and link control message encapsulation, payload segmentation and reassembly, and radio Link Layer Control Messaging.

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The integrated Network-Enhanced Telemetry (iNET) project conducted an assessment to determine how the Test and Training Enabling Architecture (TENA) would integrate into an iNET Telemetry Network System (TmNS), particularly across constrained environments on a resource constrained platform. Some of the key elements investigated were quality of service measures (throughput, latency, and reliability) in the face of projected characteristics of iNET Data Acquisition Unit (DAU) devices including size, weight, and power (SWAP), and processing capacity such as memory size and processor speed. This paper includes recommendations for both the iNET and TENA projects.

In advent of the Semantic Web and recent standardization efforts, Ontology has quickly become a popular and core semantic technology. Ontology is seen as a solution provider to knowledge based systems. It facilitates tasks such as knowledge sharing, reuse and intelligent processing by computer agents. A key problem addressed by Ontology is the semantic interoperability problem. Interoperability in general is a common problem in different domain applications and semantic interoperability is the hardest and an ongoing research problem. It is required for systems to exchange knowledge and having the meaning of the knowledge accurately and automatically interpreted by the receiving systems. The innovation is to allow knowledge to be consumed and used accurately in a way that is not foreseen by the original creator. While Ontology promotes semantic interoperability across systems by unifying their knowledge bases through consensual understanding, common engineering and processing practices, it does not solve the semantic interoperability problem at the global level. As individuals are increasingly empowered with tools, ontologies will eventually be created more easily and rapidly at a near individual scale. Global semantic interoperability between heterogeneous ontologies created by small groups of individuals will then be required. Ontology mapping is a mechanism for providing semantic bridges between ontologies. While ontology mapping promotes semantic interoperability across ontologies, it is seen as the solution provider to the global semantic interoperability problem. However, there is no single ontology mapping solution that caters for all problem scenarios. Different applications would require different mapping techniques. In this thesis, we analyze the relations between ontology, semantic interoperability and ontology mapping, and promote an ontology-based semantic interoperability solution. We propose a novel ontology mapping approach namely, OntoMogic. It is based on first order logic and model theory. OntoMogic supports approximate mapping and produces structures (approximate entity correspondence) that represent alignment results between concepts. OntoMogic has been implemented as a coherent system and is applied in different application scenarios. We present case studies in the network configuration, security intrusion detection and IT governance & compliance management domain. The full process of ontology engineering to mapping has been demonstrated to promote ontology-based semantic interoperability.

ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CA / One of the initial control room capabilities to be demonstrated by iNET program is the ability to provide data displays in the control room that do not contain data dropouts. This concept is called PCM Backfill where PCM data is both transmitted via traditional SST and recorded onboard via an iNET compatible recorder. When data dropouts occur, data requests are made over the telemetry network to the recorder for the missing portions of the PCM data stream. The retrieved data is sent over the telemetry network to the backfill application and ultimately delivered to a pristine data display. The integration of traditional SST and the PCM Backfill capability provides both real-time safety of flight data side-by-side with pristine data suitable for advanced analysis.

In advent of the Semantic Web and recent standardization efforts, Ontology has quickly become a popular and core semantic technology. Ontology is seen as a solution provider to knowledge based systems. It facilitates tasks such as knowledge sharing, reuse and intelligent processing by computer agents. A key problem addressed by Ontology is the semantic interoperability problem. Interoperability in general is a common problem in different domain applications and semantic interoperability is the hardest and an ongoing research problem. It is required for systems to exchange knowledge and having the meaning of the knowledge accurately and automatically interpreted by the receiving systems. The innovation is to allow knowledge to be consumed and used accurately in a way that is not foreseen by the original creator. While Ontology promotes semantic interoperability across systems by unifying their knowledge bases through consensual understanding, common engineering and processing practices, it does not solve the semantic interoperability problem at the global level. As individuals are increasingly empowered with tools, ontologies will eventually be created more easily and rapidly at a near individual scale. Global semantic interoperability between heterogeneous ontologies created by small groups of individuals will then be required. Ontology mapping is a mechanism for providing semantic bridges between ontologies. While ontology mapping promotes semantic interoperability across ontologies, it is seen as the solution provider to the global semantic interoperability problem. However, there is no single ontology mapping solution that caters for all problem scenarios. Different applications would require different mapping techniques. In this thesis, we analyze the relations between ontology, semantic interoperability and ontology mapping, and promote an ontology-based semantic interoperability solution. We propose a novel ontology mapping approach namely, OntoMogic. It is based on first order logic and model theory. OntoMogic supports approximate mapping and produces structures (approximate entity correspondence) that represent alignment results between concepts. OntoMogic has been implemented as a coherent system and is applied in different application scenarios. We present case studies in the network configuration, security intrusion detection and IT governance & compliance management domain. The full process of ontology engineering to mapping has been demonstrated to promote ontology-based semantic interoperability.