WiMAX与EPON融合接入网在电力通信中的应用研究

电力通信是智能化电网的重要支撑,它要求高速、安全、便捷.WiMAX与EPON融合接入网具有高带宽、成本低廉、接入灵活、易于维护等特点,可以良好的满足电力应急通信、智能营销、配电自动化等电力专网业务,为电网的全面智能化提供通信保障.     

新一代移动通信测试技术探讨

新一代移动通信系统包括目前的3G移动通信系统、下一代B3G/4G移动通信系统,以及无线宽带通信系统。论述了新一代移动通信测试技术在系统和终端设备研制生产中的需求,给出了3G通信系统测试、3GPP数据增强系统测试、CDMA2000-1X高速数据传输测试、3GPP LTE通信系统测试、WiMAX通信系统测试、B3G/4G通信系统测试和UWB无线通信测试技术的方向与重点。     

WiMAX最新标准研究

分析了WiMAX标准的分类方法、标准名称、通过时间、发布时间和当前状态,并从参考模型、网络控制与管理系统、网络参考模型、通用分组汇聚子层和媒质无关切换等方面对WiMAX最新标准IEEE802.19g-2007标准进行了研究.最后,对IEEE 802.16k标准的原理和应用进行了详细介绍.     

未来TD-SCDMA及WiMAX发展战略思考(下)

重点论述了TD-SCDMA及WiMAX的发展新动向、优势、作用与面临的挑战,及互补、融合发展战略思考。     

宽带无线接入技术WiMAX

WiMAX作为一种新兴的宽带无线接入技术,一经提出便受到了业界的普遍关注。它的主要技术特点是传输速率高、覆盖范围大、支持移动性、提供QoS保证并采用基于全IP的网络架构,实现了数据分组化、接入宽带化和终端移动化三者合一,因而具有广泛的应用前景。本文将对该技术及标准的发展情况进行概述,并在与第3代蜂窝移动通信系统进行对比的基础上分析了未来宽带无线接入的发展趋势。     

IEEE 1588协议在WiMAX基站定时中的应用

针对目前WiMAX基站必须使用GPS接收机的现状,本文提出采用IEEE 1588协议来实现基站与中心局的同步,该协议优良的特性使其成为一种方便可靠而成本低廉的替代方案.     

Performance Analysis of Uplink Scheduling Algorithms for VoIP Services in the IEEEE 802.16e OFDMA System

While the voice over Internet protocol (VoIP) services is expected to be widely supported in wireless mobile networks, the performance of VoIP services has not previously been evaluated in the IEEE 802.16e orthogonal frequency division multiple access (OFDMA) system taking the adaptive modulation and coding scheme into consideration. To support real-time uplink service flows, three different types of scheduling have been designed in the IEEE 802.16e standard: the unsolicited grant service (UGS), the real-time polling service (rtPS), and the extended rtPS (ertPS). In this paper, we compare the three real-time scheduling algorithms in terms of the performance of VoIP services by using the analytical and simulation models that we developed.

WiMAX系统部署研究

作为一种宽带无线解决方案,WiMAX系统的覆盖范囤大,且无须耗资建设昂贵的有线设施.与有线网络相比,它具有成本高效和部署迅速等优势.给出了WiMAX系统的部署模型,介绍了WiMAX系统的组网结构,列举了WiMAX系统的部署场景,分析了WiMAX系统的网络配置.     

A Survey of Various Schedulers Used for Fair Bandwidth Allocation in WiMAX: IEEE 802.16

ABSTRACT

Wireless Interoperability for Multiple Access (WiMAX) is one of the emerging fields of high-speed wireless communication that has enormous capabilities due to its range and the connection speed. Like wireless local area networks (LANs), WiMAX networks implement multiple quality of service (QoS) frameworks at the Media Access Control (MAC) level for assured data, voice, and video services. The question of ensuring QoS is basically how to distribute available resources to users in order to satisfy QoS parameters such as latency, jitter and throughput requirements. IEEE 802.16 standard does not have any particular guidelines on scheduling of incoming and outgoing data. This has caught the attention of researchers working on WiMAX. This article discusses the various issues in WiMAX along with a classification of various scheduling approaches based upon the type of scheduler for the sake of better understanding the scheduling problem and analyzing various available theories.     

Exploiting WiMAX for covert transmission of secret data over fading channel

Worldwide Interoperability for Microwave Access (WiMAX) is the broadband wireless access technique that provides rapid broadband services to domestic and enterprise users. Owing to the broadcast characteristic of the WiMAX system, transmitted data security is crucial, particularly when the messages are confidential. In this work, exploiting of WiMAX to convey sensitive secret information is presented. In the first phase, we exploited conventional WiMAX (fast Fourier transform [FFT]‐WiMAX), and in the second phase, we propose a wavelet packet transform (WPT)–based WiMAX for covert communication. The quality evaluation of both covert transmission models (FFT‐WiMAX and WPT‐WiMAX) over the fading channel is done in this work. The experimental outcomes of the proposed WPT‐WiMAX covert transmission system reveal a significant enhancement in error rate (bit error rate) and peak signal‐to‐noise ratio for a given signal‐to‐noise ratio.