网络编码在WiFi组播中的应用研究.doc

文档介绍：
网络编码在 WiFi 组播中的应用研究#
潘鲁远1,2,周亚建1,2**
(1. 北京邮电大学信息安全中心,北京 100876;
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2. 北京邮电大学灾备技术国家工程实验室,北京 100876)
摘要:随着多媒体业务的发展,组播在 WiFi 网络中的应用越来越普遍,而传统的 WiFi 接
入点 AP 在组播/广播模式下性能急剧恶化。网络编码作为一种可以压缩比特信息流的编码
机制,允许中间节点对接收到的数据进行编码,在各接收端对应的进行解码获取信息,能够
提高网络吞吐量,均衡负载和增强系统的健壮性。本文把网络编码引入到 WiFi 组播的通信
场景中,提出一种结合网络编码的 ARQ 方案,AP 节点利用无向图中的最大簇划分模型,选
择合适的编码策略,减少丢包重传次数。仿真实验表明,该算法以较低的计算复杂度,有效
的提高了系统容量和平均数据传输速率。
关键词:网络编码;WiFi 组播;自动请求重传;簇模型
中图分类号:TP393
Research work Coding in WiFi Multicast
PAN Luyuan1,2, ZHOU Yajian1,2
(1. Information Security Center, Beijing University of Posts and munications, Beijing
100876, China;
2. National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of
Posts and munications, Beijing 100876, China)
Abstract: With the rapid development of multimedia services, the implementation of multicast
mode in work is more and mon, but the performance of traditional WiFi access
point (AP) in multicast/broadcast mode deteriorated sharply. As a coding method press
the data flow, Network coding allows the intermediate node bine the data flow received
from different nodes and each node decode the corresponding data at the receive end, thus
Network Coding can work throughput, work load, and enhance robustness
of the system. This paper work Coding into the WiFi munication
scenario, and propose a new ARQ scheme based work Coding, the AP node use the cluster
model in an undirected graph to find the optimal coding schema, and reduce the number of packet
loss retransmissions. Simulation results show the algorithm can improve the system capacity and
average data transfer bandwidth effectively at a relative plexity.
Key words: Network Coding; WiFi Multicast; ARQ; Cluster Modeling
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0 引言
近年来,随着无线网络的迅速发展,WiFi 因为其较低的构建和运营成本、较高的传输
速率、较远的传输距离等优点获得了人们的青睐。随着手机电视等移动广播业务的发展,
WiFi 在组播场景中的应用将会越来越普遍,但由于各客户端与接入点之间的信道状况差异,
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无线网络需要调整数据速率来适应所有的用户节点,为确保距离无线接入点最远的节点可以
接收到正确的数据包,无线网络通过降低数据速率来适应所有的用户,因此高效的组播对于
无线网络而言是一个很大的挑战[