long-distance wireless data delivery, and may replace DSL. (Digital Subscriber Line) or cable as a last-mile solution. In addition, WiMAX can be used in mobile ...
www.ietdl.org Published in IET Communications doi: 10.1049/iet-com.2010.9049
In Special Issue on WiMAX Integrated Communications
ISSN 1751-8628
Guest Editorial WiMAX Integrated Communications WiMAX (Worldwide Interoperability for Microwave Access), which is based on IEEE (Institute of Electrical and Electronics Engineers) 802.16 standards, is an emerging radio access technology aimed at providing broadband and long-distance wireless data delivery, and may replace DSL (Digital Subscriber Line) or cable as a last-mile solution. In addition, WiMAX can be used in mobile environments to provide high-bandwidth services such as IPTV (Internet Protocol Television) and video games. Thus, WiMAX is an important access technology in next-generation wireless networks. There are many challenges in WiMAX on how to offer quality of service, reduce interference and power consumption, provide mobility management, offer various multimedia services and create secure communications. The goal of this Special Issue is to explore the researchorientated results, trials and pilot studies to solve various problems and challenges foreseen in future for WiMAX. The call for papers for this Special Issue has attracted 18 submissions from Asia, Europe and US covering many topics related to WiMAX. Each paper was carefully evaluated by at least two reviewers. Based on the review results, we selected 9 high quality research papers from the Special Issue submissions and one paper recommended by the Editor-in-Chief to be included in this Special Issue. We believe that the selected papers will provide significant information to researchers, engineers, and students working in the WiMAX and wireless communication areas. We would like to give special thanks to Prof. Habib F. Rashvand (Editor-in-Chief) and Mr. Paul Rowley for their great support and efforts on the preparation of this Special Issue. Assistance from the editorial staff of IET Communications is also very much appreciated. We would like to thank all authors who have submitted their valuable works to this Special Issue. Finally, the Guest Editors wish to gratefully acknowledge the support of all the reviewers
IET Commun., 2010, Vol. 4, Iss. 9, pp. 1037 – 1038 doi: 10.1049/iet-com.2010.9049
who have generously given their time to review the papers submitted to this Special Issue. The 10 papers are divided into three categories. Three articles discuss physical-layer issues. ‘Link Adaptation based on Repetition Coding for Mobile WiMAX Systems’ by Rong-Terng Juang et al. applies a repetition coding scheme, which encodes the same data on a subcarrier pair, to hierarchical modulation to reduce Inter-Carrier-Interference (ICI) and provide a better granularity of modulation order for link adaptation. ‘Cooperative Base Station beamforming in WiMAX Systems’ by Zhiyong Chen et al. studies zeroforcing beamforming for cooperative base stations in a downlink multi-cell Multiple Input Multiple Output (MIMO) system. A power allocation policy is proposed to reduce the capacity loss under per base station power constraints. ‘Capacity-Aware Linear MMSE Detector for OFDM-SDMA Systems’ by Ahmed Iyanda Sulyman and Mostafa Hefnawi presents a capacity-aware Linear Minimum Mean Square Error (MMSE) detector for Orthogonal Frequency Division Multiplexing-Space Division Multiple Access (OFDM-SDMA) applications. Specifically, this article derives closed-form expressions for the Signal-to-Interferenceplus-Noise Ratio (SINR) performance of OFDM-SDMA systems with linear MMSE detection method. Four articles focus on Media Access Control (MAC)-layer issues. ‘Fairness-based Scheduling Algorithm for TDD Mode IEEE 802.16 Broadband Wireless Access Systems’ by Sheng-Tzong Cheng et al. studies the fairness issue of scheduling algorithm and proposes an algorithm with fair strategy to simultaneously achieve the QoS requirements of high-priority service flows and reduce starvations of lowpriority service flows. ‘A Hierachical Scheduling Framework for QoS Service in WiMAX PMP Networks’ by Maode Ma attempts to achieve a high utilisation ratio while providing QoS supports to various applications. This article proposes a
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www.ietdl.org 3-tier architecture and the scheduling schemes in WiMAX Point to Multi-Point (PMP) networks. ‘Performance Enhancement and Analysis for IEEE 802.16e/m Sleep Mode Operations with UGS/RT-VR Connections’ by Chung-Hsien Hsu and Kai-Ten Feng proposes an adaptive listening window (ALW) approach to enhance the performance of sleep mode operations. The ALW approach dynamically adjusts the length of listening window based on the number of both arrival and retransmission packets as well as the delay constraint. ‘Secure and Reliable Transmission Mechanism for OFDMA WiMAX Systems’ by Jenhui Chen and Chih-Chieh Wang proposes a fault-tolerant transmission mechanism (FTM), which periodically adjusts mapping patterns for Base Station (BS) to control the burst size and allocates transmission slots. Three articles investigate application-layer issues and application performance. ‘Resource management to increase connection capacity of real time streaming in mobile WiMAX’ by Yueh-Min Huang et al. proposes a scheduling mechanism to perform adaptive admission control and QoS provision with consideration of user stream buffer. ‘Basic Limits for Fixed WiMAX Optimisation Based in Economic Aspects’ by Fernando J. Velez et al. proposes a model to compute the supported physical throughput as a function of the achievable Carrier-to-Noise-plusInterference Ratio (CNIR) for fixed WiMAX. The basic limits for system capacity and cost/revenue optimisation have been obtained by considering simple hypotheses in this article. ‘M-Taiwan Experience in VoIP-WiMAX Trial’ by Yi-Bing Lin et al. investigates the performance of a WiMAX-based Voice over IP (VoIP) established under the Mobile Taiwan (M-Taiwan) field-trial funded program. The measurement results in the form of Mean Opinion Score (MOS), packet loss, packet delay and jitters are presented in this article. We hope readers can enjoy reading the great selection of papers covering various aspects of WiMAX communications. REN-HUNG HWANG National Chung Cheng University, Chia-Yi County, Taiwan WU-HSIAO HSU Ming-Chuan University, Tao-Yuan County, Taiwan WHAI-EN CHEN National Ilan University, I-Lan County, Taiwan
1038 & The Institution of Engineering and Technology 2010
Ren-Hung Hwang received his B.S. degree in computer science and information engineering from National Taiwan University, Taipei, Taiwan, in 1985, and the M.S. and Ph.D. degrees in computer science from University of Massachusetts, Amherst, Massachusetts, USA, in 1989 and 1993, respectively. He joined the Department of Computer Science and Information Engineering, National Chung Cheng University, Chia-Yi, Taiwan, in 1993, where he is now a distinguished professor of the department of Computer Science and Information Engineering. His research interests include ubiquitous computing, peer-to-peer applications, wireless networks, and e-Learning.
Wu-Hsiao Hsu received the Ph.D. degree in Department of computer Science and Information Engineering from Tamkang University, Taipei County, Taiwan in 1999. He is currently a chair and associate professor in department of computer science and information engineering at Ming-Chuan University, Taoyuan Country, Taiwan. From 2000 to 2003, he served in the Eastern Multimedia Corporation (EMC) as a CTO and consultant, and was responsible for planning the ISP IP infrastructure and IDC operation. His recent research interests include QoS unicast/multicast routing, traffic engineering and IPv6.
Whai-En Chen received his B.S. degree in Electric Engineering from Tam Kang University in 1997, and received a Ph.D. in Computer Science from National Tsing Hua University in 2002. He began serving as a Research Assistant Professor in National Chiao Tung University from 2002 to 2007. Since August 2007, Dr. Chen served as an assistant professor in Institute of Computer Science and Information Engineering (CSIE). He served as the head of network division of computer and IT center from Aug. 2007 to Feb. 2010. Since Sep. 2008, he served as the director of Institute of CSIE. His research interests include IP Multimedia Subsystem (IMS), Voice over IP (VoIP), IPv4/IPv6 translation, IP mobility management, and IEEE 802.16 (WiMAX).
IET Commun., 2010, Vol. 4, Iss. 9, pp. 1037 – 1038 doi: 10.1049/iet-com.2010.9049
