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Informationen zum Autor Osama Aboul-Magd holds a Bachelor of Science degree in Electrical Engineering from Cairo University, as well as an M.A.Sc. and Ph.D. from the University of Toronto. As a Senior Advisor for Nortel Networks, he is involved in the planning and design of QoS and traffic management features for many products covering multiple technologies including Frame Relay, ATM, IP, and Ethernet. In addition to his interest in WLAN QoS and MAC related issues, Mr. Aboul-Magd has made numerous contributions to the standards development community. He was a key leader in the ATM Traffic Management specification at the ATM Forum and editor of the Ethernet Traffic Management Specification at the Metro Ethernet Forum. Mr. Aboul-Magd also co-authored the IETF (MPLS WG) proposed standard, Constraint-Based LSP Setup Using LDP and was a primary author of the OIF optical user-network interface (O-UNI) implementation agreement, OIF2000.125.6, Sept. 2001. In 2003, he began participating in the IEEE 802.11 Working Group, increasing his involvement in the standards development process. Throughout his career, Mr. Aboul-Magd has developed over twelve patents in various technology arenas. Klappentext This book is part of the IEEE Standards Wireless Networks Series. This book describes Wireless Local Area Networks Quality of Service enhancements. Those enhancements enable the support of real-time applications such as voice and video. The scope of the book includes: - Overview of QoS mechanisms and architectures. - WLAN QoS mechanisms and relationship to QoS general architectures. - Performance analysis and case studies. WLAN QoS planning and engineering are challenging tasks to both network operators and end users. This book is an attempt to satisfy the need for better understanding of WLAN QoS features as well as the related engineering challenges. The reader will be able to understand WLAN QoS mechanisms and features in a simple and clear way beyond that obtained by just reading standard documents. The reader of the book should be able to understand: - WLAN QoS basic operation. How WLAN QoS is related to other QoS architectures especially IP QoS, and the related interworking issues. - How to tackle WLAN QoS main issues including admission control, scheduling, and buffer management. How to engineer a WLAN-based network to support QoS-based applications. Inhaltsverzeichnis Preface xi Acronyms xv Chapter 1 Quality of Service Mechanisms and Metrics 1 Traffic Management Mechanisms 1 Traffic Conditioning 4 The Metering Function 5 Marker 9 Dropper 9 Shaper 10 Admission Control 11 Nodal Mechanisms 15 Transmission Scheduler 15 Buffer Management 22 Feedback Congestion Management 26 Performance Metrics 31 Throughput 32 Delay 33 Packet Loss 36 Simple Queueing Models 36 M\M\l Queueing System 38 M\G\ 1 Queueing System 41 Chapter 2 QoS Architectures 43 Reservation Model 43 Reservation Model Example 45 Service Types 49 Differentiation Model 54 Differentiating Model Examples 56 IEEE Standard 802. IQ Ethernet Frame Priority 62 Chapter 3 IEEE Standard 802.11 Overview 65 IEEE 802.11 Architecture and Frame format 65 IEEE 802.11 PHY Overview 69 IEEE 802.1 la PHY 69 IEEE 802.1 lb PHY 71 The IEEE 802.1 lg PHY Overview 73 The IEEE 802.11 MAC Overview 75 Distributed Coordination Function (DCF) 75 Point Coordination Function (PCF) 81 Power Management 85 IEEE 802.11 Throughput 86 IEEE 802.11 Frame Types 90 A Queueing Model for PCF Performance 92 Chapter 4 IEEE 802.11 QoS Features 97 IEEE 802.1 le MAC Overview 97 Data Frame Format 99 Association to QoS BSS 102 EDCA Operation 105<...
