基于数值仿真的PTN实时性业务传输时延研究

发布时间：2018-11-08 12:11

【摘要】：随着智能电网进程的加快,电力通信网络服务面临从SDH技术向IP分组技术的升级。大颗粒、多类型网络业务的出现,迫使以时分复用为核心的电力通信传输网向统计复用进行转变,这就为PTN技术提供了广阔的应用前景。通常情况,继电保护和安全稳定控制等电力系统实时性业务采用时分复用技术来构建传输通道,此类业务对时延的要求极高,这对传输通道的可靠性和实时性提出了挑战。PTN承载此类实时性业务需要具备充分的理论支持和充足的仿真数据支撑。以往对于PTN网络实时性业务传输时延的研究,大多以网络测试为主,较少出现的理论研究也没有考虑传输时延的随机性问题和时延抖动问题。本文采取数值仿真的方法,深入研究了实时性业务的传输时延问题。建立了PTN分组传输的随机时延模型,该模型可以表示随机传输时延概率分布,并可以研究分组封装尺寸对传输时延特性的影响。提出了随机封装和固定封装两种分组封装模式,分别建立了单节点和串联路径端到端时延抖动数学模型。定量研究了背景流量、网络节点数量、路由器吞吐量等参数对时延抖动的影响程度,对比分析了两种封装模式的优缺点。为了验证时延抖动数学模型的正确性,编程实现了时延抖动模型的蒙特卡罗仿真。数值仿真结果表明,随着分组封装尺寸的不断增加,随机传输时延概率呈现快速增长的趋势。背景流量对随机封装模式影响较大,对固定封装模式影响很小。节点数量的增多会显著增大时延抖动。时延抖动随路由器吞吐量的增加而减小。在网络参数均相同的条件下,固定封装模式的时延抖动值更小。蒙特卡罗仿真验证了时延抖动模型的正确性。采用非结构化封装的实时性业务,当封装数量处于16~32区间时,具有良好的时延特性。通过控制传输通道参数,能够有效减少时延抖动,从而为宿边缘路由器去抖动设置提供依据。在绝大多数情况下,固定封装比随机封装拥有更好的稳定性和抗时延抖动能力。本课题的研究成果为PTN承载TDM业务提供了理论支持,在改善电力通信实时性业务传输时延方面具有一定的技术指导意义和工程参考价值。
[Abstract]:With the acceleration of smart grid process, power communication network services are facing upgrading from SDH technology to IP packet technology. The emergence of large particle and multi-type network services forces the power communication transmission network with time division multiplexing as the core to change to statistical multiplexing which provides a broad application prospect for PTN technology. In general, the real-time services of power system such as relay protection, safety and stability control adopt time-division multiplexing technology to construct transmission channels, which require very high time delay. It is a challenge to the reliability and real-time of the transmission channel, and it is necessary for PTN to carry such real-time services with sufficient theoretical support and sufficient simulation data support. In the past, most of the researches on the real-time transmission delay of PTN network mainly focused on network testing, and the few theoretical studies did not consider the randomness of transmission delay and the problem of delay jitter. In this paper, the transmission delay of real-time traffic is studied by numerical simulation. The random delay model of PTN packet transmission is established. The model can represent the probability distribution of random transmission delay and study the effect of packet package size on transmission delay characteristics. Two packet encapsulation modes, random package and fixed package, are proposed, and the mathematical models of end-to-end delay jitter of single node and series path are established respectively. The influence of background traffic, number of network nodes and router throughput on delay jitter is quantitatively studied, and the advantages and disadvantages of the two encapsulation modes are compared and analyzed. In order to verify the correctness of the delay jitter mathematical model, Monte Carlo simulation of the delay jitter model is programmed. The numerical simulation results show that the probability of random transmission delay increases rapidly with the increasing of packet package size. Background flow has a great influence on random packaging mode, but little effect on fixed packaging mode. The increase in the number of nodes will significantly increase the delay jitter. Delay jitter decreases with the increase of router throughput. When the network parameters are the same, the delay jitter of fixed encapsulation mode is smaller. Monte Carlo simulation verifies the correctness of the delay jitter model. The real-time service with unstructured encapsulation has good delay characteristics when the number of packages is in the range of 16 ~ 32. By controlling the transmission channel parameters, the delay jitter can be effectively reduced, thus providing the basis for setting up the dejitter of the host edge router. In most cases, the fixed package has better stability and resistance to delay jitter than random packaging. The research results of this paper provide theoretical support for PTN carrying TDM services, and have certain technical guiding significance and engineering reference value in improving the transmission delay of real-time power communication services.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN915.853;TM73

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