Asynchronous Transfer Mode (ATM) protocol was designed to support real-time traffic steams over high quality links like fiber optics where the transmission error is extremely low. ATM performs poorly in an error-prone environment such as wireless communications. The purpose of this research is to investigate error control schemes in wireless ATM (W-ATM) to support real-time service, such that the physical layer error conditions are handled in lower layers under ATM transport layer. Automatic Repeat reQuest schemes (ARQ) and Forward Error Correction (FEC) have been widely used for reliable data transmissions. However, the current existing ARQ schemes can potentially introduce unbounded delay in high error rate environments like W-ATM network due to the lack of delay control mechanism. As a result, they are not appropriate for real-time data communications in which there are strict packet delay requirements. In this dissertation, we explored the issues related to W-ATM area. Adaptation of FEC, specifically Reed-Solomon code, to channel error conditions in W-ATM is investigated. The quality-of-service (QoS)-aware error control algorithm is originated and its performance is evaluated. The algorithm is further simplified to make it more suitable for practical applications. The requirements of ARQ applicability for real-time communication environment like W-ATM is extensively analyzed. An ARQ scheme, called D-bit protocol, is developed to satisfy the real-time requirements. The scheme supports reliable packet discarding while allowing retransmissions without compromising user-level QoS for real-time stream applications. Simulations show the effectiveness and liveness of the protocol. / Ph. D.

Abstract Wireless communication and monitoring have been applied in military and other related engineering for couples of year. The application concept of this technology is now initiating in family life and the power monitoring of home scale combined with network and wireless communication will be setup in this study. This thesis is based on the use of PIC 16F877 microprocessor as main unit to catch the equipment information and treat the process of state control. The interchange control between information and main computer will be employed by RF wireless modulus. The drawing-type interface of human/machine is designed by using the software of Labview. The internet obeying agreements of TCP/IP communication combined with global movable communication of GSM will be built up to carry out the wireless remote control for safety-management system of power equipment by fast information transfer. This system was approved to meet the define requirements through the processes of analysis¡Bdesign¡Bmanufacturing and test.

No description available.

abstract: A quantitative analysis of a system that has a complex reliability structure always involves considerable challenges. This dissertation mainly addresses uncertainty in- herent in complicated reliability structures that may cause unexpected and undesired results. The reliability structure uncertainty cannot be handled by the traditional relia- bility analysis tools such as Fault Tree and Reliability Block Diagram due to their deterministic Boolean logic. Therefore, I employ Bayesian network that provides a flexible modeling method for building a multivariate distribution. By representing a system reliability structure as a joint distribution, the uncertainty and correlations existing between system’s elements can effectively be modeled in a probabilistic man- ner. This dissertation focuses on analyzing system reliability for the entire system life cycle, particularly, production stage and early design stages. In production stage, the research investigates a system that is continuously mon- itored by on-board sensors. With modeling the complex reliability structure by Bayesian network integrated with various stochastic processes, I propose several methodologies that evaluate system reliability on real-time basis and optimize main- tenance schedules. In early design stages, the research aims to predict system reliability based on the current system design and to improve the design if necessary. The three main challenges in this research are: 1) the lack of field failure data, 2) the complex reliability structure and 3) how to effectively improve the design. To tackle the difficulties, I present several modeling approaches using Bayesian inference and nonparametric Bayesian network where the system is explicitly analyzed through the sensitivity analysis. In addition, this modeling approach is enhanced by incorporating a temporal dimension. However, the nonparametric Bayesian network approach generally accompanies with high computational efforts, especially, when a complex and large system is modeled. To alleviate this computational burden, I also suggest to building a surrogate model with quantile regression. In summary, this dissertation studies and explores the use of Bayesian network in analyzing complex systems. All proposed methodologies are demonstrated by case studies. / Dissertation/Thesis / Doctoral Dissertation Industrial Engineering 2018

The architecture of the network is undergoing a series of structural changes from the core network to the user to pave the way for 5G. New infrastructure elements are being massively deployed, thus making 5G more heterogeneous. This emerging paradigm, along with new services and handheld devices, creates a massive, highly mobile, heterogeneous environment with hard constraints in throughput, latency, resilience, and power consumption. This dissertation presents Agile MEC (AMEC), a shift in the concept of MEC to support user's mobility with the rapid relocation of services; and Network-coded Cooperation (NCC), a new system for massive content distribution in cellular networks. In summary, AMEC provides a mobility framework that reliably reduces the latency and power consumption in the system, and NCC improves network throughput, network resilience, and power consumption by offloading cellular traffic to underlay networks. / Die Architektur des Netzes durchläuft eine Reihe von strukturellen Veränderungen vom Kernnetz bis zum Benutzer, um den Weg für 5G zu ebnen. Neue Infrastruktur Elemente werden massiv eingesetzt, wodurch 5G heterogener wird. Dieses aufkommende Paradigma bildet zusammen mit neuen Diensten und Handheld-Geräten eine massive, hochmobile, heterogene Umgebung mit harten Einschränkungen in Bezug auf Durchsatz, Latenz, Belastbarkeit und Stromverbrauch. In dieser Dissertation werden Agile MEC (AMEC), eine Verschiebung des MEC-Konzepts zur Unterstützung der Mobilität der Benutzer durch die schnelle Verlagerung von Diensten, und Network-coded Cooperation (NCC), ein neues System zur massiven Verteilung von Inhalten in zellularen Netzwerken, vorgestellt. Zusammenfassend lässt sich sagen, dass AMEC einen Mobilitätsrahmen bietet, der die Latenzzeit und den Stromverbrauch im System zuverlässig reduziert, und NCC verbessert den Netzwerkdurchsatz, die Netzwerkstabilität und den Stromverbrauch, indem es den zellularen Datenverkehr auf unterlagerte Netzwerke verlagert.