基于跨层的卫星网络协议研究
文献类型:学位论文
作者 | 张梅山 |
学位类别 | 硕士 |
答辩日期 | 2008-06-03 |
授予单位 | 中国科学院研究生院 |
授予地点 | 中国科学院软件研究所 |
导师 | 刘立祥 |
关键词 | 卫星网络 跨层设计 SaclTCP协议 拥塞控制 NS网络仿真 |
其他题名 | Research on Cross-Layer Based Protocol for Satellite Networks |
学位专业 | 计算机应用技术 |
中文摘要 | 卫星网络的固有特性如大时延、高误码、链路不对称和资源匮乏等特点, 使得TCP/IP协议无法为卫星网络提供令人满意的服务,因此设计适应卫星网络的特点新型网络协议以是一个值得深入研究的问题。采用跨层设计思想可以减少层次网络的冗余性,实时获取网络状态信息,通过调整数据传输方式,使得网络具有自适应性,并能显著提高卫星网络的性能。本文提出了基于跨层的卫星网络协议SaclTCP,它针对TCP协议的拥塞控制策略提出改进:在物理层将链路有效带宽信息反馈给传输层,使传输层了解物理链路容量的大小,准确的设定拥塞窗口门限阈值;在数据链路层将链路丢包事件通知给传输层,使传输层对丢包原因做出正确的判断;在网络层对路由器缓冲队列进行管理,一方面以一定的概率发送显示拥塞通知,另一方面计算网络拥塞状况,传输层利用这些信息动态调节拥塞窗口的大小。最后,在NS-2环境下对SaclTCP仿真,并与传统TCP协议进行比较。实验结果表明,SaclTCP协议在传输性能上有大幅度提高,更适合卫星网络环境,同时也证明了基于跨层的卫星网络协议设计的正确性和可行性。 |
索取号 | 暂无 |
英文摘要 | Satellite network has some special characteristics, such as the big propagation delay, high bit-error rate, asymmetric channels and limited resources, and these characteristics make TCP/IP protocols incapable of providing satisfying service for satellite network. As a result, designing new network protocols which is suitable for satellite network is important. The idea of cross-layer design can reduce the redundancy of multi-layer, capture net status information at any moment , and so it can adjust the data transfer methods to make the network self-adaptive, thus increasing the performance of satellite network greatly. This article puts forward a new satellite network transport layer protocol-SaclTCP based on the idea of cross-layer. The protocol advances an amelioration scheme of cross-layer aiming at congestion control strategy of TCP. This protocol can send back the effective bandwidth information to transport layer from physical layer, so the transport layer will know the size of link capacity and enactment window congestion gate-limit threshold. it can also let data link layer notify the link packet lose errors to transport layer, therefore the transport layer can make correct judgments of these errors. It brings forward router buffer queue managing mechanism, which could send and display the congestion message on definite probability one side, and compute the network congestion condition on the other side. The transport layer will use these information to regulate the size of window dynamically. The last part includes emulation experiment of SaclTCP via NS-2 and the performance comparison with traditional transport protocols. The results indicate that SaclTCP protocol has great elevation on transport performance, and it is more suitable for satellite network environment. At the same time, it demonstrates the validity and feasibility of satellite network protocol bases on cross-layer. |
公开日期 | 2011-03-17 |
分类号 | 暂无 |
源URL | [http://124.16.136.157/handle/311060/5644] ![]() |
专题 | 软件研究所_综合信息系统技术国家级重点实验室 _学位论文 |
推荐引用方式 GB/T 7714 | 张梅山. 基于跨层的卫星网络协议研究[D]. 中国科学院软件研究所. 中国科学院研究生院. 2008. |
入库方式: OAI收割
来源:软件研究所
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