An overview of next-generation mobile WiMAX technology - [WiMAX update]

The growing demand for mobile Internet and wireless multimedia applications has motivated the development of broadband wirelessaccess technologies in recent years. Mobile WiMAX has enabled convergence of mobile and fixed broadband networks through a common wide-area radio-access technology and flexible network architecture. Since January 2007, the IEEE 802.16 Working Group has been developing a new amendment of the IEEE 802.16 standard (i.e., IEEE 802.16m) as an advanced air interface to meet the requirements of ITU-R/IMT-advanced for 4G systems, as well as for the next-generation mobile network operators. Depending on the available bandwidth and multi-antenna mode, the next-generation mobile WiMAX will be capable of over-the-air datatransfer rates in excess of 1 Gb/s and of supporting a wide range of high-quality and high-capacity IP-based services and applications while maintaining full backward compatibility with the existing mobile WiMAX systems to preserve investments and continuing to support first-generation products. This tutorial describes the prominent technical features of IEEE 802.16m and the potential for successful deployment of the next generation of mobile WiMAX in 2011+.     

WiMAX技术讲座——第1讲 WiMAX技术概述

通过不同设备供应商提供的、具有互操作功能的兼容设备,WiMAX可用于提供建设成本低、兼容程度高、互操作性强的BWA解决方案。本文介绍了WiMAX的产生背景,分析了WiMAX的技术优势,给出了WiMAX的参考模型,归纳了国内外应用现状,阐明了WiMAX发展面临的挑战,预测了WiMAX技术的发展趋势。     

3G移动无线宽带技术与WiMAX性能分析

语音、彩信、图像和视频等业务正在快速增加无线网络的通信量．使得用户和网络经营商谋求更高容量的网络技术来维持其应用和运营。本文比较了WiMAX／OFDMA与WCDMA之间的主要技术．以获得一种具有高移动数据网络能力与成本效率的最佳方案。     

WiMAX技术讲座第1讲 WiMAX技术概述

通过不同设备供应商提供的、具有互操作功能的兼容设备,WiMAX可用于提供建设成本低、兼容程度高、互操作性强的BWA解决方案。本文介绍了WiMAX的产生背景,分析了WiMAX的技术优势,给出了WiMAX的参考模型,归纳了国内外应用现状,阐明了WiMAX发展面临的挑战,预测了WiMAX技术的发展趋势。     

Ethernet services over mobile WiMAX

Ethernet services represent a steadily growing portion of the fixed telecommunication market. To enable the provisioning of Ethernet services over IEEE 802.16e, the mobile WiMAX network architecture supports transparent Ethernet transport as an optional extension to the IP services architecture. Ethernet support is tightly aligned to the IP services network model, and leverages many data path and control plane functions from its IP sibling to keep the implementation and operation overhead low for the Ethernet extension. Mobile WiMAX provides IP services as well as Ethernet services over the same mobile access network. The intrinsic mobility support may create new deployment opportunities for Ethernet services. Initially, the Ethernet extension may be mostly used to realize wireless access for DSL networks based on the same network interfaces defined for the wired Ethernet-based DSL aggregation.     

移动宽带技术的演进路线及解决方案

介绍了移动宽带通信技术发展的历程,阐述了3GPP、3GPP2和LTE3种主流移动宽带技术的演进路线．对移动宽带和固定宽带技术在性能和网络构架上进行了比较,并就移动宽带网络建设方案和应用场景进行了探讨。     

Adaptive STBC-VBLAST transmission for mobile WiMAX

Multiple-input multiple-output (MIMO) technology can provide high data rate and substantial diversity. Space time block code (STBC) provides diversity gain and obtains signal of better quality even under bad channel conditions. However, it has no contribution to system average throughput. Vertical-bell laboratory layered space-time (VBLAST) improves peak data rate but leads to higher packet error rate (PER) at cell edge when the channel condition is poor. To get both higher system average throughput and cell edge throughput, an adaptive STBC-VBLAST transmission for downlink mobile WiMAX system is proposed and analyzed through system-level simulation in this article. The proposed approach compares the effective capacity of two candidate MIMO modes (STBC or VBLAST) and reports its decision to the base station with only one extra signaling bit. The simulation results show that the proposed approach can attain a balance between STBC and VBLAST. Besides, the cell throughput approximates that of pure VBLAST and the cell edge throughput is close to that of pure STBC.     

4G移动通信技术发展概述

文章说明在不同频带的网络中,或者在不固定的无线平台中,4G都可以提供无线网络,并且除了通信,还有其他的功能,例如:采集数据、远程控制、定位等等。     

浅谈WiMAX技术及其应用

简单论述了WiMAX的标准、关键技术及应用场景，展望了宽带移动通信的发展前景．并从无线管理的角度提出了几点思考。     

Utility-based admission control for mobile WiMAX networks

This paper presents a novel utility-based connection admission control (CAC) scheme for IEEE 802.16e broadband wireless access networks. We develop specific utility functions for real-time and non-real-time services coupled with a handover process. Given these utility functions we characterize the network utility with respect to the allocated bandwidth, and further propose a CAC algorithm which admits a connection that conducts to the greatest utility so as to maximize the total resource utilization. The simulation results demonstrate the effectiveness of the proposed CAC algorithm in terms of network utility.     

Mobile WiMAX systems: performance and evolution

Mobile WiMAX was successfully adopted by ITU as one of the IMT-2000 technologies in November 2007. Since then mobile WiMAX (a.k.a. IP-OFDMA) has officially become a major global cellular wireless standard along with 3GPP UMTS/HSPA and 3GPP2 CDMA/ EVDO. Mobile WiMAX is an OFDM-based technology available for deployment today, and new WIMAX devices come to market at much reduced cost than that of current 3G solutions. Currently over 260 service providers are deploying fixed, portable and mobile WiMAX networks in 110 countries. This article provides an overview of the mobile WiMAX system and its performance under various configurations, channel conditions, and types of data traffic. Furthermore, the article provides an overview of mobile WiMAX evolution.     

WiMAX加速移动互联网时代的到来

WiMAX（微波接入全球互通）是一种无线宽带数据传输系统。目前，该技术正在计划和试用阶段，同时，用于首次区域性实验的相关无线网络也已经开始建设，企业正与从事WiMAX相关领域研究的专家们进行着密切的合作。     

Capacity estimation and TCP performance enhancement over mobile WiMAX networks - [WiMAX update]

The mobile WiMAX system is based on IEEE 802.16e, which defines radio interface supporting several classes of Internet Protocol applications and services. While the mobile WiMAX system is being deployed, IEEE 802.16m TG is developing an amendment to the IEEE 802.16e to greatly improve the system performance, and it is focusing not only on the PHY and MAC performance but also on a level of end-to-end performance improvement that includes the scope of the network and application to embrace the strong market request and interest. To evaluate the mobile WiMAX system capacity and performance, all the aspects of performance evaluation ? from air link to application ? are required. For the network and application-level capacity and performance analysis, we first provide an overview of mobile WiMAX systems, especially of the OFDMA/TDD systems of IEEE 802.16e and then describe subscriber and application profiles that include traffic-mix ratio, data-session attempts for applications, diurnal-application traffic distribution, and the application-traffic model. Afterward, the simulation results of network- traffic characteristics and demand estimation are provided. Finally, in the last section, we provide simulation results of end-to-end application performance evaluation using the examples of VoIP and a TCP/IP performance-enhancement method that can be implemented in the mobile WiMAX MAC or MAC/IP cross layer.     

Handover management in integrated WLAN and mobile WiMAX networks [recent advances and evolution of WLAN and WMAN standards]

Recently there has been much effort, in both academia and industry, to integrate a plethora of wireless technologies in order to provide ubiquitous broadband access to mobile users. Handover management is still one of the most challenging issues to be solved for seamless integration of wireless networks. This article addresses the integration of IEEE 802.11 WLANs and IEEE 802.16 WMANs, focusing mainly on the handover management aspects. First, we describe architectures, futuristic application scenarios such as the envisioned heterogeneous multihop wireless networks (HMWNs) and moving networks, as well as the related research issues. Second, we present IEEE 802.21, a new emerging standard aimed at providing a framework for media-independent handover (MIH) among heterogeneous networks. Finally, we discuss how the MIH framework can help handover management for the integrated network.     

Seamless integration of mobile WiMAX in 3GPP networks

As the wireless industry makes its way to the next generation of mobile systems, it is important to engineer solutions that enable seamless integration of emerging 4G access technologies within the currently deployed and/or evolved 2G/3G infrastructures. In this article we address a specific case of such a seamless integration, that of mobile WiMAX in evolved 3GPP networks. In this context we investigate the architecture and the key procedures that enable this integration, and we also introduce a novel handover mechanism that enables seamless mobility between mobile WiMAX and legacy 3GPP access, such as UTRAN or GERAN. The core characteristic of this novel handover mechanism is that mobile terminals do not need to support simultaneous transmission on both WiMAX and 3GPP accesses; therefore, it mitigates the RF coexistence issues that exist otherwise and improves handover performance. In addition, we provide a brief overview of mobile WiMAX and the evolved 3GPP network technologies, and we set the appropriate background material before presenting our proposed handover mechanism. Our main conclusion is that integrating mobile WiMAX in evolved 3GPP networks is a compelling approach for providing wireless broadband services, and mobility across WiMAX and 3GPP access can become seamless and efficient with no need for mobile terminals to support simultaneous transmission on both types of access.     

Seamless IP mobility support for flat architecture mobile WiMAX networks - [WiMAX update]

The growing demand for wireless Internet services is accelerating the evolution of wireless networks toward all-IP architecture, and the mobile WiMAX network is a prominent example. Although currently deployed mobile WiMAX networks use hierarchical architecture, flat architecture is feasible and specified as a design alternative in the mobile WiMAX standard. In flat architecture the functionalities of the ASN-GW and BS are consolidated into a single element. In this article we first discuss the benefits and challenges of flat architecture mobile WiMAX networks. We then present a scheme to deal with the seamless mobility issue, which is one of the key challenges of the flat architecture. The proposed scheme combines two standard IP-mobility protocols, Proxy Mobile IP and Fast Mobile IP, and customizes them for IEEE 802.16e-based mobile WiMAX networks. This provides interoperability with existing mobile WiMAX networks. We demonstrate the viability of the proposed scheme through simulations using NS-2.     

Measurement and analysis of online gaming services on mobile WiMAX networks

Online games have been played mainly in desktop computers over wired networks because of high speed and intensive computation requirements. The advances in mobile devices and ever increasing wireless link bandwidth motivate us to study whether players can enjoy online gaming over broadband wireless networks such as mobile Worldwide Inter‐operability for Microwave Access (WiMAX). In this paper, we carry out comprehensive measurements of the World of Warcraft (WoW) over the mobile WiMAX in Seoul, Korea, and analyze the network performance focusing on two aspects: (1) network layer dynamics such as round trip time, jitter, and packet loss and (2) WiMAX link layer statistics such as the radio signal strength, handovers, and piggyback mechanism. From the empirical data, we set up performance models and evaluate the performance of WoW over WiMAX. We also discuss how to improve the service quality of online gaming over WiMAX.Copyright © 2013 John Wiley & Sons, Ltd.     

Mobile WiMAX: a technology update

The success and growth of Internet-based services has profoundly impacted the global economies, as well as the ways people communicate and their lifestyles. With ever increasing demands for accessing the Internet via mobile devices, the focus of next-generation mobile wireless technology development is to enable and efficiently deliver broadband mobile multimedia and Internet services to users. The communication industry is making big strides in the design of next-generation broadband mobile networks which are poised to enormously increase the value of the Internet and its usage by bringing the Internet to users as opposed to having users go to the Internet.     

QoE-aware mobile IPTV channel control algorithm over WiMAX network

In this paper, we present an effective IPTV channel control algorithm that improves the quality of experience for subscribers to mobile IPTV services over WiMAX network. We consider the video quality of TV channels and the channel zapping time as quality of experience metrics. The proposed algorithm controls the channel distribution state and the target bit rate of TV channels based on the channel preference information of subscribers to achieve an effective trade-off between channel zapping time and video quality. Finally, simulation results are provided to demonstrate the performance of the proposed system.