A method for estimating local traffic load in a simulcast radiosystem

This paper presents a simple method for estimating the average local traffic load in a simulcast radio system. Such estimation is crucial to achieving efficient resource sharing and dynamic reconfiguration of the simulcast areas. The proposed method is based only on relative power measurements at each radio port (or distributed antenna element) and is applicable to both code-division multiple-access (CDMA) and time-division multiple-access (TDMA) systems. Simulation results are derived to test the method over various system conditions and assumptions. The proposed method is shown to provide excellent results, giving estimates to within ±15% of the actual Erlang traffic, while requiring only an approximate knowledge of the radio propagation environment     

面向开源路由设备的I2RS加速技术设计与实现

南向协议接口标准I2RS（路由系统接口）是传统网络向SDN（软件定义网络）过渡过程中出现的一种新标准。基于该标准,提出了一种直接利用地址访问内核空间数据的方法,从而能够使南向接口以更高效率获取单点路由设备状态和各类统计信息的方法,给出了方法的实现过程,并对采用本方法提取数据的速度、访问数据出错次数以及从异常中恢复的时间进行了大量、长时间的测试。实验测试结果表明,与现有技术相比,本方法提取信息的速率明显提高,并且在提取信息出现异常时能够快速从异常中恢复。在实际网络环境中的应用表明,该方法发挥了快速可靠提取信息的作用。     

Entropy of ATM traffic streams: a tool for estimating QoSparameters

For the purposes of estimating quality-of-service parameters, it is enough to know the large deviation rate-function of an ATM traffic stream; modeling procedures can be bypassed if we can estimate the rate-function directly, exploiting the analogy between the rate-function and thermodynamic entropy. We show that this proposal is soundly based on statistical sampling theory. Experiments on the Fairisle ATM network at the University of Cambridge have established that it is feasible to collect the required data in real time     

A method for estimating the parameters of the K distribution

A method that combines the maximum likelihood and the method of moments for estimating the parameters of the K distribution is proposed. The method results in the lowest variance of parameter estimates when compared with existing non-ML techniques     

GMPLS-based photonic multilayer router (Hikari router)architecture: an overview of traffic engineering and signalingtechnology

A new extended signaling and traffic engineering method for the GMPLS-based photonic and electrical multilayer router (Hikari router) is proposed. The method allows dynamic optical network management and photonic signal recovery, such as regeneration, reshaping, etc., to be realized adaptively. Wavelength conversion is also adaptive, which reduces network cost. Multilayer traffic engineering, which yields the dynamic cooperation of IP and photonic layers, is described to provide IP services cost effectively. To realize multilayer traffic engineering, we propose the OSPF extension, which advertises both the number of total wavelengths and the number of unused wavelengths, and the RSVP-TE extension, which minimizes the number of wavelength conversions needed. In addition, this paper proposes a heuristics-based multilayer topology design scheme that uses IP traffic measurements in a generalized multi-protocol label switch (GMPLS). The proposed scheme yields the optical label switch path (OLSP) network topology, that is, OLSP placement, that minimizes network cost, in response to fluctuations in IP traffic demand. In other words, the OLSP network topology is dynamically reconfigured to match IP traffic demand. Networks are reconfigured by the proposed scheme so as to utilize network resources in the most cost effective manner     

A simple method for estimating rain attenuation distribution

This paper deals with a method for estimating rain attenuation distribution at frequencies above 10 GHz. This method depends only on point rainfall rate. Based on statistical independence among rain cells, a relation connecting cell dimension, path distance, precipitation and attenuation is established. Numerical results have shown good agreement with experimental data.     

A novel method for estimating the SNR of unknown emitter signal

It is important to estimate the Signal-to-Noise Ratio(SNR) of unknown emitter signal accurately.In order to resolve the disadvantages of present algorithm,a novel method is proposed in this letter.We extract and normalize the information of zero frequency of received signal by the Wigner-Vile Distribution(WVD) transformation and then get the approximate power of original signal by mathematic transformation,at last,we get the estimate value of SNR by the known account formula of SNR.Simulation results show t...     

An agile optical layer restoration method for router failures

The optical layer can provide its IP clients with rapid and efficient restoration for link failures; however, its inability to protect against router failures erodes its attractiveness. Here, we propose a joint IP/optical restoration mechanism suitable for IP offices with a minimum of two backbone routers and an optical cross-connect. The OXC is used to reterminate OC-48/OC-192 links from a failed backbone router to its mate. The entire interoffice portion of the reterminated link is reused, thus minimizing the amount of additional link capacity required to protect against router failures. A similar approach applicable when there are tunable transceivers but no OXC is also described.     

一种低复杂度的二维波达方向估计方法

提出了一种基于传播算子的低复杂度二维波达方向估计新算法,该方法避免了常规子空间方法中占主要运算量的估计信号协方差矩阵及其高维矩阵的特征分解,降低了运算复杂度,并且由于无阵列孔径损失,获得了良好的参数估计性能.最后计算机仿真验证了算法的有效性.     

A simple method for estimating the spectrum of exponentially damped sinusoidal signals

An algorithm is presented for the spectrum of experimentally obtained exponentially damped sinusoidal signals. The implementation of this algorithm is straightforward and requires only simple basic mathematical operations. Applications of the algorithm are illustrated by several examples.     

A globally convergent and consistent method for estimating the shape parameter of a generalized Gaussian distribution

We propose a novel methodology for estimating the shape parameter of a generalized Gaussian distribution (GGD). This new method is based on a simple estimating equation derived from a convex shape equation. The estimating equation is completely independent of gamma and polygamma functions. Thus, no lookup table, interpolation, or additional subroutine to evaluate these functions are required for real-time implementations of the proposed method, which is in contrast to all existing methods. Furthermore, we establish that the shape equation has a unique global root on the positive real line and the Newton-Raphson root-finding algorithm converges to the unique global root from any starting point in a semi-infinite interval Theta_min. More importantly, we show that the sample-based shape estimating equation has a unique global root with probability tending to one and the root is consistent for the true shape parameter. Finally, we prove via fixed point arguments that, with probability tending to one, the Newton-Raphson algorithm converges to the unique global root of the sample shape estimating equation from any starting point in Theta_min. Some numerical experiments are also provided to demonstrate the global convergence and the excellent finite sample performance of the proposed method     

一种新的动态流量疏导算法

基于层叠网络模型,将饱和割集的方法应用于IP over WDM光网络的动态流量疏导中.该方法通过提取IP层网络的拓扑特征,并应用该特征触发多种方式建立光路,增加了在光层建立光路的灵活性.仿真结果显示,该方法可以有效降低网络阻塞率.     

A graphical method for detection of Flash Crowds in traffic

Majority of traffic analysis tools today are based on NetFlow technology including its more recent successor, IPFIX protocol. Even with the flexibility of IPFIX in mind, processing traffic in realtime is still difficult. Given the urgent need for lightweight methods in the area, this paper is crossing inter-disciplinary borders to find a solution. Specifically, this paper looks into a possibility of applying video compression to 2D visualization of traffic in search for anomalies. The proposed method is applied to detection of Flash Crowds in traffic and is found successful when compared to other methods.     

A new structure-preserving method of sampling for predicting self-similar traffic

The paper presents a structure-preserving method of sampling self-similar traffic with an application to network monitoring and resource provisioning. Based on the observation of the self-similarity of Internet traffic, we propose a new sampling technique (so-called the maximum-based sampling). We show that the resulting data suits perfectly for predicting the bandwidth required by upcoming traffic so that the resource provisioning can be done efficiently and intelligently especially for the context of IP over WDM networks. Hence, we prove mathematically that the proposed technique preserves the self-similarity of the traffic. Besides, experimental results using real Internet traffic show that unlike other sampling techniques (systematic sampling and stratified random sampling), the maximum-based sampling capture faithfully the traffic self-similarity. In order to assess the effect of the sampling technique impact on the performance of the traffic prediction,we undertake a series of prediction experiments using sampled traffic with the proposed technique and the other sampling techniques. A neurofuzzy model (α _SNF), the AutoRegressive Integrated Moving Average model (ARIMA) and the Linear Minimum Mean Square Error (LMMSE) are considered in this study for bandwidth prediction. Our experiments results show that the maximum-based sampled traffic—used for the identification of the prediction model—is the most suitable for predicting the traffic for different time scales.     

A TENSOR ANALYSIS METHOD FOR ESTIMATING 3-D MOTION PARAMETERS

By using the center projection image sequence to estimate 3-D motion parameters,one needs to know the corresponding relationship between the feature of motion object in spaceand the projection coordinate on image plane.In order to avoid using the relationship of featurecorrespondence,the tensor analysis method in the affine transformation system is presented,andthe simulation data of experimental results are given.     

一种网络流量平稳化方法

由于网络流量的不稳定性,会影响流量模型的准确性。平稳化的目的是使得流量成为平稳或更为接近平稳,以提高流量模型的准确性。差分是一种常用的平稳化方法,它对具有线性趋势的时间序列有很好的平稳化效果。本文提出一种统计分析的方法对流量进行平稳化处理,可以在一定程度上消除流量不稳定性对流量建模的影响。     

千兆位路由器的线卡设计

介绍了1Gb/s速率的核心路由器中线卡的体系结构,并从设计的角度对一些主要的功能模块进行了分析,详细论述了线卡转发引擎中基于FPGA的设计与实现,经过时序仿真与系统测试,验证了线卡设计的正确性.     

A refined bootstrap method for estimating the Zernike polynomial model order for corneal surfaces

Following our previous work on optimal modeling of corneal surfaces with Zernike polynomials, we have developed a refined bootstrap-based procedure which improves the accuracy of the previous method. We show that for normal corneas, the optimal number of Zernike terms usually corresponds to the fourth or fifth radial order expansion of Zernike polynomials. On the other hand, for distorted corneas such as those encountered in keratoconus or in surgically altered cases, the estimated model was found to be up to three radial orders higher than for normal corneas.     

一种城市单路口交通两级模糊控制方法

依据单路口4个方向车流信息,提出一种单路口交通两级模糊控制方法,采用模糊控制技术,无需建立精确的教学模型,对两相位的交叉路口,是一种基于车辆等待长度的单点信号交叉口交通实时模糊控制方法.根据城市交通实际状况,在考虑每个相位的关键车流和非关键车流的车辆到达交叉口信息的基础上,提出更有效的单路口交通实时模糊控制方法,并时该控制器进行仿真研究,仿真结果达到预期要求.