In leicht verständlichem Stil erläutern die Autoren dieses Buches Anforderungen an Multiple-Access-Protokolle für den Mobilfunk. Zu Beginn werden zellulare Kommunikationssysteme der 2. und 3. Generation eingeführt. Ausführlich beschrieben werden dann MA-Protokolle für paketorientierte zellulare Systeme. Ein großer Teil der vorgestellten Resultate stammt aus eigenen Forschungsarbeiten der Autoren, u.a. zur Verbesserung der Protokolle und zur Modellierung der physikalischen OSI-Schicht.

This cutting-edge, first-of-its-kind resource gives you a comprehensive understanding of the simulation and evaluation methods used for today's mobile communication systems. Written by two highly regarded experts in the field, the book focuses on the performance of both the physical and protocol layer transmission scheme. It defines and presents several invaluable simulation tools written in MATLAB® code, along with clear examples that explain their use.

As the demand for broadband services continues to grow worldwide, traditional solutions, such as digital cable and fiber optics, are often difficult and expensive to implement, especially in rural and remote areas. The emerging WiMAX system satisfies the growing need for high data-rate applications such as voiceover IP, video conferencing, interactive gaming, and multimedia streaming. WiMAX deployments not only serve residential and enterprise users but can also be deployed as a backhaul for Wi-Fi hotspots or 3G cellular towers. By providing affordable wireless broadband access, the technology of WiMAX will revolutionize broadband communications in the developed world and bridge the digital divide in developing countries. Part of the WiMAX Handbook, this volume focuses on the technologies behind WiMAX, its performance capabilities, and its control mechanisms. The book introduces programmable baseband processors suited for WiMAX systems, describes an innovative methodology for the design of multi-band WiMAX antennas, addresses space-time block codes, and reviews space-frequency/space-time-frequency code design criteria. It also proposes a combined call admission control and scheduling scheme, focuses on the performance analysis of the IEEE 802.16 mesh mode, and analyzes the performance of both single-input-single-output and space-time-block-coded OFDM systems in mobile environments. The final section establishes a framework of an ideal reservation period controller, examines the ecosystem in which scheduling for IEEE 802.16e systems must be performed, and presents a fuzzy logic controller for admission control. With the revolutionary technology of WiMAX, the lives of many will undoubtedly improve, thereby leading to greater economic empowerment.

This book constitutes the refereed proceedings of the 4th International IFIP-TC6 Networking Conference, NETWORKING 2005, held in Waterloo, Canada in May 2005. The 105 revised full papers and 36 posters were carefully reviewed and selected from 430 submissions. The papers are organized in topical sections on peer-to-peer networks, Internet protocols, wireless security, network security, wireless performance, network service support, network modeling and simulation, wireless LAN, optical networks, Internet performance and Web applications, ad-hoc networks, adaptive networks, radio resource management, Internet routing, queuing models, monitoring, network management, sensor networks, overlay multicast, QoS, wirless scheduling, multicast traffic management and engineering, mobility management, bandwith management, DCMA, and wireless resource management.

The convergence of wireless communication and the Internet is one of the strongest emerging markets in the telecommunications industry. This book consists of a compilation of papers on key issues related to 3G and 4G wireless communications and wireless access to next generation Internet (NGI). Included in Multiaccess, Mobility and Teletraffic for Wireless Communications: Volume 5 are new results on space-time access schemes that can dramatically increase the achievable bit rates of wireless systems, perhaps approaching bandwidth efficiencies in the order of 10 bits/s/Hz. The book also considers broadband wireless access to NGI. Effective management of radio resources in wireless systems is necessary for high spectral efficiency and to support mobility. This book treats issues relating to handoff and channel assignment in cellular frequency reuse systems. In order to achieve quality of service (QoS) expectations in a dynamically changing wireless environment, effective error and QoS control protocols are needed. To guarantee fairness in the access to resources, medium access control (MAC) protocols are needed. Optimization of network resources traffic and mobility models are also needed, along with effective call admission control strategies. All of these topics are covered herein. Finally, this book considers future 3G and 4G wireless systems and highlights the critical challenges that must be overcome to make these systems a commercial reality. Multiaccess, Mobility and Teletraffic for Wireless Communications: Volume 5 is an important book for researchers, students and professionals working in the area of wireless communications and mobile computing.

Organized into three parts, Resource, Mobility, and Security Management in Wireless Networks and Mobile Communications examines the inherent constraint of limited bandwidth and unreliable time-varying physical link in the wireless system, discusses the demand to realize the service continuity in the single-hop or multi-hop wireless networks, and ex

This is an authoritative description of the range of future mobile communications technologies.

Relay systems have become a subject of intensive research interest over the recent years, as it is recognized that they can improve performances and extend the coverage area of wireless communication systems. Special attention has been dedicated to them since the proposal appeared for their implementation in mobile cellular systems. Numerous researches conducted after that proposal have enabled incorporation of OFDM based relay systems in both accepted standards for IMT-Advanced systems. Nowadays, researches are ongoing with the aim to define new solutions for performance improvement of the standardized OFDM relay systems for cellular networks and one of the interesting solutions is implementation of subcarrier permutation (SCP) at the relay (R) station.The book OFDM based relay systems for future wireless communications presents a comprehensive research results in analyzing behavior and performance of the OFDM based relay systems with SCP. Dual-hop relay scenario with three communication terminals, and no direct link between the source (S) and the destination (D) has been analyzed, as it is compliant with the accepted solutions for IMT-Advanced systems. The book includes performance analysis and performance comparison of OFDM based:• amplify-and-forward (AF) relay systems with fixed gain (FG),• amplify-and-forward (AF) relay systems with variable gain (VG),• decode-and-forward (DF) relay systems,each including two SCP schemes, known to maximize the system capacity and/or improve the bit error rate (BER) performances. Performance comparisons have enabled definition of optimal solutions for the future wireless communication systems in a given conditions, and for the given optimality criteria. OFDM based relay systems for future wireless communications contains recent research results in this area and is ideal for the academic staff and master/research students in area of mobile communication systems, as well as for the personnel in communication industry.

Computer communication networks have come of age. Today, there is hardly any professional, particularly in engineering, that has not been the user of such a network. This proliferation requires the thorough understanding of the behavior of networks by those who are responsible for their operation as well as by those whose task it is to design such networks. This is probably the reason for the large number of books, monographs, and articles treating relevant issues, problems, and solutions in this field. Among all computer network architectures, those based on broadcast mul tiple access channels stand out in their uniqueness. These networks appear naturally in environments requiring user mobility where the use of any fixed wiring is impossible and a wireless channel is the only available option. Because of their desirable characteristics multiple access networks are now used even in environments where a wired point-to-point network could have been installed. The understanding of the operation of multiple access network through their performance analysis is the focus of this book.

As the research for future fourth generation (4G)mobile communication systems has been launched worldwide in major companies and academic institutions, forward-thinking professionals are striving to gain a thorough understanding of the cutting-edge technologies and design techniques that will make these systems work. This unique new book helps you do just that. It provides you with a comprehensive introduction to multicarrier techniques for 4G mobile communications with a special focus on the analytical aspects. Radio channel characteristics and phenomena are explained along with discussions on the advantages and disadvantages of OFDM scheme. You get in-depth explanations of new multicarrier-related techniques, MC-CDMA, research on several 4G systems and a look at several problems to be overcome regarding these systems.