网络可靠组网与高效传输关键技术研究

发布时间：2018-07-04 21:15

  本文选题：平均距离 + 节点不相交路径　； 参考：《电子科技大学》2014年博士论文

【摘要】：随着网络的快速发展,越来越多的高清图片和音视频应用使得网络的流量呈指数增长,而网络的建设远跟不上网络的发展,因此需要一个高效的网络以支撑各种应用和业务的开展。电子商务、在线支付等应用的飞速发展要求网络要具有较好的实时性;而各种自然灾害、攻击和破坏要求网络能够应对各种故障,因此一个高效可靠的网络拓扑和传输机制显得十分重要。网络拓扑是网络高效、可靠传输的基础,故障恢复用来保护网络的可靠传输,高效的传输机制保证信息的高效传输,高效可靠的网络拓扑和高效的传输机制共同促进整个网络的高效可靠运行。本文在详细分析网络拓扑优化、故障保护以及基于无速率码的传输等方面研究现状的基础上,指出进一步提高网络高效可靠需要研究的问题,针对这些问题,本文在高效可靠网络拓扑优化、链路故障保护、高效无速率码设计等方面展开了一系列研究,并在以下几个方面取得了一些有价值的研究成果:1.高效网络拓扑优化设计在给定节点和链路数量下,设计一种基于平均距离的网络拓扑优化算法。该算法利用网络拓扑邻接矩阵的特点来降低运算量,该算法分两步实现最佳网络拓扑的选择:第一,通过计算网络拓扑的平均距离,算法有可能找到多个具有最小平均距离的网络拓扑;第二,进一步计算每个节点和链路故障后的平均距离,并选出故障后平均距离最小的网络拓扑作为最优的网络拓扑。2.节点之间具有最多节点不相交路径和最大节点连通度的网络拓扑设计提出一种在任意两个节点之间具有最多的节点不相交路径且具有较高节点连通度的网络模型,设计了在给定节点和链路数量下设计满足上述模型的算法,并通过采用一些技巧降低运算量。计算结果表明,该算法所设计的网络既满足节点不相交路径要求又能达到或者接近网络的理论节点连通度。将高效性和可靠性相结合给出了设计既具有最多的节点不相交路径和较大节点连通性,又有较小平均距离的网络拓扑设计算法。3.基于网络编码的多链路故障保护改进一种基于网络编码的方法实现在相同数量主路径情况下用最少的保护路径实现对多个链路故障的保护,该方案不仅考虑主路径故障的情况,同时也考虑了保护路径故障的情况。4.无速率码的性能指标及理想模型在分析当前无速率码性能指标的缺点和适用范围的基础上,提出新的性能指标,并推广了传统系统码的定义,然后提出一种理想的无速率码模型来全面描述无速率码。5.基于两阶段前向等概的无速率码设计以理想无速率码模型为基础,提出一种基于两阶段前向等概的无速率码设计算法,仿真结果表明该算法编出的无速率码具有较高的码率、较小的平均延时、较小的最大失序和较大的均匀恢复熵。将两阶段前向等概编码算法稍做修改可以用于不等差错保护,同样具有上述的性能优势。对于无法知道信道精确状况但知道其最坏状况的情形,给出一种在已知最大擦除概率情况下的无速率码的设计,仿真表明其性能相比无任何先验知识的设计算法性能略有提高。最后分析了编码算法对译码算法的影响,分析表明,该编码算法可以大大降低高斯消元法和BP译码算法的运算量。6.基于环的高效无速率码设计组成一个文件的每个信息符号之间并不是孤立的,而是存在一定的关联性,本文将这种关联性应用在无速率的设计中并结合高效性提出一种基于环的高效无速率码的设计方案,该方案除了有较好的性能之外,更接近于真实的通信环境。7.基于效率-公平的无速率码设计虽然基于两阶段和前向等概的编码算法有很好的性能,但该性能只是平均意义下的性能,无法保证每一次通信的性能都能满足要求。本文通过修正理想无速率码模型,给出基于新模型的无速率码设计算法。该算法基于效率和公平原则,并通过确定性和随机性相结合提高性能,仿真结果表明该算法具有较好的性能。对该算法稍作修改,便可以用于不等差错保护,同样具有较好的性能。
[Abstract]:With the rapid development of the network, more and more high-definition pictures and audio and video applications have made the network traffic exponential growth, and the construction of the network is far from the development of the network. Therefore, an efficient network is needed to support the development of various applications and services. The rapid development of electronic commerce, line payment and other applications requires the network to have The network topology and transmission mechanism is very important. The network topology is the basis of high efficient network and reliable transmission, the fault recovery is used to protect the reliable transmission of the network, and the efficient transmission mechanism ensures the information. Efficient transmission, efficient and reliable network topology and efficient transmission mechanism jointly promote the efficient and reliable operation of the whole network. On the basis of detailed analysis of network topology optimization, fault protection and rate based transmission based on rate code transmission, this paper points out that further research on high network efficiency and reliability needs to be studied. Some studies have been carried out in the aspects of efficient and reliable network topology optimization, link failure protection, high efficient rate code design and so on, and some valuable research achievements have been obtained in the following aspects: 1. design a network topology based on the average distance under the given node and the number of chain paths. The algorithm uses the characteristics of the network topology adjacency matrix to reduce the computational complexity. The algorithm divides the optimal network topology into two steps. First, by calculating the average distance of the network topology, it is possible to find a number of network topologies with minimum average distance; second, each node and link fault can be further calculated. The network topology with the best network topology as the optimal network topology, which has the most node disjoint path and the maximum node connectivity, presents a network topology that has the most node disjoint paths between any two nodes and has higher node connectivity among the two nodes. The network model designs the algorithm designed to satisfy the above model under the number of given nodes and links, and reduces the computation by using some techniques. The calculation results show that the network designed by the algorithm not only satisfies the node disjoint path requirements but also can reach or close to the connectivity of the theoretical nodes of the network. The network topology design algorithm,.3., which has the most nodes not intersecting paths, larger nodes connectivity, and smaller average distance, is based on network coded multi link fault protection improvement. A network coding based method is used to implement multiple chains with the least protection path in the same number of main paths. The scheme not only takes into account the failure of the main path, but also considers the performance index of the.4. rate code and the ideal model, based on the analysis of the shortcomings of the current rate code performance index and the scope of application, and extends the definition of the traditional system code, and then the definition of the traditional system code is extended. An ideal rate free code model is proposed to fully describe the rate code.5. based on the two phase forward probability code based on the ideal rate code. Based on the ideal rate free code model, a rate code design algorithm based on the two phase forward equal probability is proposed. The simulation results show that the rate code produced by the algorithm has a high bit rate and is smaller. The average delay, the smaller maximum loss order and the larger uniform recovery entropy. The two phase forward equivalent coding algorithm is modified to be used for unequal error protection. It also has the above performance advantage. For the case where the channel precision is not known but the worst case is known, a given maximum erasure probability is given. The design of the rate free code shows that the performance of the design algorithm is slightly higher than that without any prior knowledge. Finally, the influence of the coding algorithm on the decoding algorithm is analyzed. The analysis shows that the algorithm can greatly reduce the computation of the Gauss elimination and BP decoding algorithm.6. based on the high efficient rate code design based on the loop. Each of the information symbols is not isolated, but there is a certain relevance. In this paper, this relevance is applied to the design of a rate free design and combined with the efficiency of the design. The scheme is more efficient and is closer to the actual communication environment,.7., based on the better performance. The rate fair rate free code design has good performance on the basis of the two phase and forward equivalent coding algorithm, but the performance is only in the mean sense, and the performance of every communication can not be guaranteed. In this paper, a new model based non rate code design algorithm is given by modifying the ideal rate free code model. The method is based on the principle of efficiency and fairness, and improves performance by combining certainty and randomness. The simulation results show that the algorithm has good performance. The algorithm can be used for unequal error protection with slight modification to the algorithm, and it has good performance.
【学位授予单位】：电子科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TP393.02
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本文编号：2097452