REALISM:一种面向未来异构无线网络演进的架构

未来无线通信系统将是各种无线接入技术和标准的融合,包容各自独立的网络,形成通用的平台并以简便的协议和信令操作,来实现异构网络融合是我们提出REALISM(REconfigurable:Adaption Layer for Integrated SysteM)的初衷,它通过在协议栈添加适配层(REAL:REconfigurable Adaption Layer),为由WLAN和UMTS组成的无线异构网络提供了融合的平台.文章重点关注了REALISM架构中的主要功能模块;然后描述了无线资源管理方面功能的实现,并以切换管理,例进行详细阐述.     

关于IEEE802.11安全机制的信息完整性

为了达到与有线网相同的安全性 ,IEEE80 2 .1 1协议在MAC层引入安全机制 ,该机制建立在协议定义的WEP (wiredequivalentprivacy)算法基础上 .WEP通过在RC4密码系统内部设置CRC 32循环冗余校验的方式来实现报文完整性验证 .本文从编码理论的基本概念出发 ,对IEEE80 2 .1 1安全机制的完整性验证能力进行分析 ,指出存在的缺陷     

IEEE802．11无线局域网的一种新的加密机制

IEEE 802．1l无线局城网的加密采用RC4加密算法，RC4算法本质上是一个伪随机数生成算法，本身有缺陷，本文在对IEEE802.11无线局城网的加密机制进行分析的基础上，引入了一种新的伪随机数生成方法——Fast packet keying，并提出了改进方案．     

A new channel allocation scheme and performance optimizing for mobile multimedia wireless networks

A multimedia channel allocation scheme is proposed and studied in terms of the connection-level QoS. A new traffic model based on multidimensional Markov chain is developed considering the traffic characteristic of two special periods of time. And the pre-emptive priority strategies are used to classify real-time services and non-real-time services. Real-time service is given higher priority for its allowance to pre-empt channels used by non-real-time service. Considering the mobility of persons in a day, which affects the mobile user＇s density, the simulation was conducted involving the two pre-emptive priority strategies. The result of some comparisons shows the feasibility of the proposed scheme.     

IEEE 802.11无线局域网的一种新的加密机制

IEEE802.11无线局域网的加密采用RC4加密算法,RC4算法本质上是一个伪随机数生成算法,本身有缺陷,本文在对IEEE802.11无线局域网的加密机制进行分析的基础上,引入了一种新的伪随机数生成方法———Fastpacketkeying,并提出了改进方案.