小生境遗传算法在网络编码优化中的应用研究

网络编码技术在提高网络吞吐量和传输效率等方面具有较大优势,但该技术需要在节点处进行额外编码操作,增加了编码开销。为通过减少编码边数量来降低编码开销,提出基于小生境遗传算法的网络编码优化算法。通过多目标优化方式来构造适应度函数,保证降低编码边数量的同时可以兼顾网络带宽利用率。该算法在小生境遗传操作中使用自适应交叉和变异概率,避免运算过程中的无效操作,提高了运算效率。实验结果表明,该算法可有效降低编码开销,与简单遗传算法相比,具有更好的收敛性,能够在更短的时间内得到更少的编码边。

NTOP精确监控网络流量

监控网络流量常用MRTG这个工具，这里介绍另一个工具——NTOP。用NTOP显示网络的使用情况比MRTG更加直观、详细。NTOP甚至可以列出每个节点计算机的网络带宽利用率。

Survivable Traffic Cognition Algorithm with Joint Failure Probability in Flexible Bandwidth Optical Networks

This paper addresses the problem of survivable traffic assignment with failure probability requirement in flexible bandwidth optical networks. We describe a Survivable Traffic Cognition (STC) algorithm with joint failure probability. Survivable Traffic Assignment (STA) algorithm and Conventional Traffic Assignment (CTA) algorithm are added to illustrate the effectiveness of our proposed STC. We investigate the effect of joint failure probability on blocking probability, spectral utilization ratio, average joint failure probability, and the average hops. Simulation results show that our proposed STC not only achieves better performance in terms of blocking probability and spectral utilization ratio than CTA and STA, but also does not cause higher average joint failure probability or larger average hops compared with STA. As a result, STC makes the best use of spectral resources and does not cause large average joint failure probability.

A Novel Optical Burst Mesh Network with Optical Time Slot Interchange at Source Nodes

In this paper, we propose an optical burst network architecture supporting the ge- netic mesh topology. The intermediate node architecture of the mesh network can be the same with current wavelength switching Wave- length Division Multiplexing （WDM） net- works, and thus can reuse existing deployed infrastructure. We employ a novel Optical Time Slot Interchange （OTSI） at the source nodes for the first time to mitigate the burst conten- tion and to increase the bandwidth utilization. Time- and wavelength-domain reuse in the OTSI significantly saves optical components and red- uces blocking probability.

A Dynamic Bandwidth Allocation Solution Based on User Behavior and Software Defined EPS

For telecommunication operators, how to improve the utilization of bandwidth resources is always a problem which worthy of study, nowadays, this issue has become more and more important, since the traffic load bursting in the mobile Internet. So the key to solving this problem is that we need to find a kind of traffic model to predict the traffic load that users need. According to the predicted traffic load to allocate bandwidth to each base station dynamically.But the traffic consumption behavior of a single base station is random, it is difficult to predict[ 1 ]. For this reason, we based on reality that, when the user moves, it may get traffic load from different base stations, therefore, there will have some kind of relationship between those base stations.We use this relationship to establish a kind of Spatial Collaborative Network.consequently, we make use of stability algorithm to divided those base station cluster into different communities, According to the traffic load usage rules which these communities indicated to us, we get a traffic model.At the same time, we studied bow to use this traffic model in the future networks to dynamically allocate bandwidth resources, then we propose a new kind of EPS architecture based on SDN, on this platform, we can deploy our strategy through it＇s programmable interface.Finally, we designed an experiment to test the performance of our dynamic strategy, and the result shows that our method enables bandwidth utilization has been greatly improved.

FUZZY-BASED NETWORK BANDWIDTH DESIGN UNDER DEMAND UNCERTAINTY

In communication networks （CNs）, the uncertainty is caused by the dynamic nature of the traffic demands. Therefore there is a need to incorporate the uncertainty into the network bandwidth capacity design. For this purpose, this paper developed a fuzzy methodology for network bandwidth design under demand uncertainty. This methodology is usually used for offiine traffic engineering optimization, which takes a centralized view of bandwidth design, resource utilization, and performance evaluation. In this proposed methodology, uncertain traffic demands are first handled into a fuzzy number via a fuzzification method. Then a fuzzy optimization model for the network bandwidth allocation problem is formulated with the consideration of the trade-off between resource utilization and network performance. Accordingly, the optimal network bandwidth capacity can be obtained by maximizing network revenue in CNs. Finally, an illustrative numerical example is presented for the purpose of verification.