跨层优化的多路友好传输研究与设计

发布时间：2019-05-23 19:38

【摘要】：近年来,随着移动互联网的大规模部署应用,为适应当今及未来泛在异构的网路接入环境,移动终端普遍使用多接口技术,方便用户随时随地访问互联网,也推动了多路传输方式的兴起与发展。多路传输具有带宽聚合、冗余容错、负载均衡等特征优势,能够提高数据吞吐量,满足内容实时性与交互性的高带宽需求,成为未来互联网数据传输的发展趋势之一。然而,在高动态的无线移动网络中,多路传输不可避免遭受数据失序与丢失问题的影响,造成传输阻塞,大大降低传输效率。现有大部分研究方案仅仅依靠传输层参数来实施数据调度,难以捕获底层无线链路的变化情况,导致数据调度的准确性和有效性不足。同时,在网络资源紧张和竞争的情况下,多路传输的并发性和贪婪性会侵占过多的带宽资源,引起对当前占主导的TCP数据流的不友好性,影响整体网络性能。针对上述问题,本文提出了一种新颖的跨层优化的多路友好传输解决方案,对现有多路传输协议进行改进,为未来移动网络服务及应用提供高效而友好的数据传输服务。本文开展了如下研究工作：(1)设计了无线链路等效测量计算方法,准确而简便获得链路层参数；(2)设计了新型的时延测量、带宽估计和速率估计算法,完善传输层参数的获取；(3)提出了基于友好性窗口的流量控制机制,结合奖励和惩罚方法,兼顾公平与效率；(4)建立了路径容量的跨层评估模型,基于丢包分析修改了重传策略,实现精确的路径管控和有效的数据适配。为评估该方案的性能,本文搭建了基于NS-2仿真平台的多组网络场景,进行了详细具体的仿真实验测试。实验结果表明,对比现有的多路传输方案,本文所提出的方案在数据吞吐量指标和TCP友好性指标上有明显优势,能够显著提高数据吞吐量,同时保证TCP友好性,优化整体网络性能,提高网络资源利用率。
[Abstract]:In recent years, with the large-scale deployment of mobile Internet applications, in order to adapt to the current and future heterogeneous network access environment, mobile terminals generally use multi-interface technology to facilitate users to access the Internet anytime and anywhere. It also promotes the rise and development of multi-channel transmission mode. Multi-channel transmission has the advantages of bandwidth aggregation, redundancy and fault tolerance, load balancing and so on. It can improve data throughput and meet the high bandwidth requirements of real-time and interactive content. It has become one of the development trends of Internet data transmission in the future. However, in high dynamic wireless mobile networks, multi-channel transmission is inevitably affected by data disorder and loss, resulting in transmission congestion and greatly reducing transmission efficiency. Most of the existing research schemes only rely on transport layer parameters to implement data scheduling, which is difficult to capture the changes of the underlying wireless link, resulting in insufficient accuracy and effectiveness of data scheduling. At the same time, under the condition of tight and competitive network resources, the concurrency and greed of multi-channel transmission will encroach on too many bandwidth resources, which will cause unfriendliness to the current dominant TCP data stream and affect the overall network performance. In order to solve the above problems, a novel cross-layer optimized multi-channel friendly transmission solution is proposed in this paper, which improves the existing multi-channel transmission protocols and provides efficient and friendly data transmission services for future mobile network services and applications. In this paper, the following research work is carried out: (1) the equivalent measurement and calculation method of wireless link is designed, and the link layer parameters are obtained accurately and easily; (2) A new algorithm of delay measurement, bandwidth estimation and rate estimation is designed to improve the acquisition of transport layer parameters. (3) A flow control mechanism based on friendliness window is proposed, which combines reward and punishment methods to take into account fairness and efficiency. (4) the cross-layer evaluation model of path capacity is established, and the retransmission strategy is modified based on packet loss analysis to achieve accurate path control and effective data adaptation. In order to evaluate the performance of the scheme, several sets of network scenarios based on NS-2 simulation platform are built in this paper, and the detailed simulation experiments are carried out. The experimental results show that compared with the existing multi-channel transmission schemes, the proposed scheme has obvious advantages in data throughput index and TCP friendliness index, and can significantly improve data throughput and ensure TCP friendliness. Optimize the overall network performance and improve the utilization of network resources.
【学位授予单位】：北京邮电大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5;TP393.01

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