HFC网络中的宽带接入技术

文中介绍了ＨＦＣ网络的结构和频谱分配，同时对ＨＦＣ网络中的接入协议作了深入分析。     

802.11基带处理芯片中GFSK调制解调系统的实现

无线局域网是一种短距离无线通信系统。本文介绍了802．11协议中GFSK的调制原理，并提出了一种低成本、低功耗的GFSK调制解调实现方案，可应用于802．11基带处理芯片的设计中。     

IEEE1149.1产生新标准

研制边界扫描原先是为了检验IC引线与PCB连接轨迹，现在它已被用于支持芯片调试、设备流程，混合信号测试和现场服务。     

WiMAX产业化现状与发展趋势分析

文章从芯片制造、终端及系统设备研发、技术试验和商业应用、产业联盟等方面对WiMAX产业化现状和商用进程进行了分析，并总结了其商用化发展的要素和面临的挑战。     

Distributed Priority Scheduling and Medium Access in Ad Hoc Networks

Providing Quality-of-Service in random access multi-hop wireless networks requires support from both medium access and packet scheduling algorithms. However, due to the distributed nature of ad hoc networks, nodes may not be able to determine the next packet that would be transmitted in a (hypothetical) centralized and ideal dynamic priority scheduler. In this paper, we develop two mechanisms for QoS communication in multi-hop wireless networks. First, we devise distributed priority scheduling, a technique that piggybacks the priority tag of a node's head-of-line packet onto handshake and data packets; e.g., RTS/DATA packets in IEEE 802.11. By monitoring transmitted packets, each node maintains a scheduling table which is used to assess the node's priority level relative to other nodes. We then incorporate this scheduling table into existing IEEE 802.11 priority backoff schemes to approximate the idealized schedule. Second, we observe that congestion, link errors, and the random nature of medium access prohibit an exact realization of the ideal schedule. Consequently, we devise a scheduling scheme termed multi-hop coordination so that downstream nodes can increase a packet's relative priority to make up for excessive delays incurred upstream. We next develop a simple analytical model to quantitatively explore these two mechanisms. In the former case, we study the impact of the probability of overhearing another packet's priority index on the scheme's ability to achieve the ideal schedule. In the latter case, we explore the role of multi-hop coordination in increasing the probability that a packet satisfies its end-to-end QoS target. Finally, we perform a set of ns-2 simulations to study the scheme's performance under more realistic conditions.     

A Centralized MAC-Level Admission Control Algorithm for Traffic Stream Services in IEEE 802.11e Wireless LANs

The admission control algorithm that can be performed at the MAC (Medium Access Control) layer in a real-time is proposed for the decision for accepting or rejecting the requests for adding traffic streams to an IEEE 802.11e wireless LAN (Local Area Network). In numerical examples, we apply the proposed admission control algorithm to VOIP (Voice Over Internet Protocol) traffic streams, and obtain the maximum numbers of VOIP traffic streams that can be admitted to IEEE 802.11a/e, IEEE 802.11b/e and IEEE 802.11g/e wireless LANs for various delay requirements.     

基于WLAN技术的无线校园网组网研究

无线局域网(WLAN)使用无线多址信道方法来支持计算机间通信。简要介绍了IEEE802.11g标准协议以及无线局域网基本原理和拓扑结构，并结合无线局域网组网特点，详细阐述设计规划无线校园网的原则、方法和步骤。最后介绍一个可行的802．11g无线校园网设计方案。     

WiMAX体系结构和应用

介绍了以IEEE802.16标准为基础的无线城域网技术WiMAX的发展过程,分析了无线城域网体系结构,包括物理层技术特点、MAC层的QoS保证机制,并对WiMAX的几种典型应用进行了分析.     

组播业务在WiMAX系统中的实现

IEEE802．16e-2005空中接口规范增加了对MBS（组播）业务的支持，使WiMAX系统的应用得到进一步扩展。文章介绍了IEEE802．16e-2005空口实现组播业务的机制，并分析了WiMAX系统提供这一业务所面临的问题。     

针对WLAN的特定攻击手段与相关检测技术

文章分析了各种针对无线局域网的攻击手段,并提出了相应的检测机制。针对基于MAC欺骗的攻击手段提出了一种基于802.11帧序列号的异常进行检测的技术,对于其它的无线网络入侵手段等则利用匹配攻击特征的方法,实现入侵检测。