面向快速切换和可靠组播的WLAN传输系统  

WLAN transmission system for fast handoff and reliable multicast

作　　者：刘轶峰 曾学文[1,2] 韩锐 孙鹏[1,2] LIU Yifeng;ZENG Xuewen;HAN Rui;SUN Peng(National Network New Media Engineering Research Center,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院声学研究所国家网络新媒体工程技术研究中心,北京100190 [2]中国科学院大学,北京100049

出　　处：《电子设计工程》2022年第12期67-73,共7页Electronic Design Engineering

基　　金：中国科学院战略性科技先导专项课题(XDC02070100)。

摘　　要：随着视频流量以及移动设备的激增,无线环境下切换和组播场景日益增多。而基于IEEE 802.11的无线局域网(Wireless Local Area Network,WLAN)无法为用户提供快速的无线切换和高效可靠的无线组播服务。基于此,该文设计并实现了集中控制的WLAN传输系统。针对快速切换,系统通过在多个接入点间同步终端上下文信息,并引导终端切换来避免传统切换时的信令交互。针对可靠组播,系统提升了组播帧的物理层发送速率,并采用喷泉码和NACK(Negative Acknowl⁃edgement)结合的方式保证无线组播传输的可靠性。实验结果表明,该文的快速切换机制比传统机制减少了200 ms延时;而相比于现有的方案,该文的无线组播方案在提供高效可靠的组播服务的同时,能够控制反馈开销。With the rapid growth of video traffic and mobile devices,handoff and multicast scenarios are increasing in wireless environment.However,IEEE 802.11-based Wireless Local Area Network(WLAN)cannot provideusers withfast wireless handoff,efficient and reliable wireless multicast.Therefore,this paper designs and implements a centralized control WLAN transmission system.For fast handoff,the system avoids the messages exchange in the traditional way by synchronizing the terminal context information among the access points and guiding the terminal handoff.Forreliable multicast,the system improves the physical layer rate of multicast frame,and adopts fountain code and NACK(Negative Acknowledgement)to ensure the reliability of wireless multicast transmission.Experimental results reveal that the delay of proposed fast handoff scheme is 200 ms less than that of the traditional scheme.Compared with the existing mechanisms,the proposed wireless multicast scheme can control the feedback overhead while providing an efficient and reliable multicast service.

关 键 词：WLAN传输系统 无线快速切换 无线组播 喷泉码 

分 类 号：TN919.6[电子电信—通信与信息系统]