移动互联网背景下RCS的探讨与分析

移动互联网的发展加快了移动OTT业务的普及,导致传统通信业务萎缩。运营商为了应对OTT业务的挑战,推出了基于IMS网络的RCS业务。本文结合RCS的发展历程及现状,介绍RCS的功能架构及系统组网;同时针对RCS业务发展所要面对的问题和挑战,分析并提出相应的发展策略,具有一定的参考价值。     

RCS与MMTel的发展演进分析

简单介绍了RCS与MMTel的功能和演进方案;详细阐述了最终用户业务和通信能力的分类,演进过程中RCS与MMTel的通信能力以及RCS与MM-Tel通信能力共存面临的问题。     

RCS业务发展情况及分析

文章对RCS(Rich Communication Suite,富通信套件)业务功能范围、标准发展历程等加以阐述,对RCS业务产业现状作出总结分析;并进一步阐述RCS对于运营商的重要价值所在:运营商借助RCS可实现基础业务升级,并在"互联网+"时代将基础通信业务延伸到物联网、家庭互联网、产业互联网等相关领域;最后提出几项RCS业务发展建议。     

RCS业务在IMS的组网方案研究

介绍RCS/RCSe业务的情况,对IMS网络开展RCS业务的组网方案进行分析和比较,对引入RCS业务的组网方案提出建议和参考。     

RCS业务运营商互通方案探讨

本文通过描述RCS业务的基本概念和组网架构，探讨了RCS业务在运营商之间互通的需求和具体方案。     

RCS体系及测试浅析

RCS(Rich Communication System)是融合了GSMA,OMA,3GPP等标准而制定的具有互操作性的IMS服务标准,本文先以RCS的发展情况,对其目前已发布的4个版本做了简要介绍,然后以2.0版本为例,分析了RCS的业务体系结构以及实验室网络环境下的业务测试,结合问题给出测试改进方案,最后对RCS业务进行了总结和展望。     

RCS发展思路探索

为了迎接互联网业务提供商向电信行业提出一次又一次挑战,电信运营商推出了RCS概念。文章阐述了RCS业务技术优势和对运营商的意义所在,分析了目前全球技术标准和产业链状态,最后从产业角度论述了对于国内运营商,RCS未来发展的思路。     

IMS的发展探讨

从长远的发展看,IMS将是固定网络和移动网络共同的核心业务控制层,据此,介绍了RCS的进展,以及RCS1.0、RCS2.0、RCS3.0等3个版本的特点;最后给出了RCS的应用示例。     

5G消息应成手机标配 行业共赢才是未来唯一出路

日前,中国移动有关负责人在会议上建议,将5G消息业务功能纳入工信部终端入网检测要求。也就是说,如果该建议被采纳,则厂商新出的5G手机必须支持RCS(融合通信)功能,否则将无法上市销售。事实上,早在几年前,GSMA就已经将RCS纳入5G终端的必选功能,而中国移动在"5G消息创新开放实验室成立暨RCS产品发布会"上就已经要求终端厂商支持该功能,可时间过去了一年多,却依然裹足不前。     

RCS业务部署关键因素分析及建议

首先介绍了GSMA发布RCS业务的背景及国内发展现状,接着针对影响RCS业务的业务部署、数据承载、终端方案、互联互通4大关键因素进行了分析,最后结合Vo Wi Fi网络特点提出部署建议。     

Control of radar cross sections of electrically small hightemperature superconducting antenna elements using a magnetic field

The radar cross sections (RCS) of small circular loops made from YBCO high temperature superconductor are calculated as a function of applied magnetic field strength. It is shown that the RCS is reduced as the magnetic field increases, and that the effect is more pronounced as radiation resistance decreases. Two factors contributing to the RCS reductions are identified, firstly an increase in surface resistance with magnetic field, and secondly a detuning effect caused by a change in the loop input reactance. It is suggested that antennas might be made from superconductor as a means of controlling their RCS, rather than for improved efficiency     

The RCS of a microstrip antenna on an in-plane biased ferritesubstrate

The numerical solutions for the RCS of a microstrip patch on an in-plane biased ferrite substrate are presented. The peaks in the RCS can be moved with respect to frequency by changing the magnetic bias field. We consider a monostatic RCS with various incident angles and examine all four elements of the cross-section matrix. For the case of an unmagnetized ferrite substrate the cross-polarized RCS components are zero. When the ferrite is magnetized, the cross-polarized RCS components become as significant as do the copolarized RCS components. It is also shown that a loaded patch has the effect of significantly reducing RCS at resonances. The analysis used is based on a full-wave moment method with the exact spectral-domain Green's function     

如何理解目标高分辨率雷达图像及其像素值

经过图像定标后的雷达图像及其像素值具有雷达散射截面（radar cross section，RCS）的量纲，但是对于该像素值是否能代表目标实际RCS电平一直存在不同的理解.本文通过引入与传统RCS定义相一致的目标散射函数和散射分布函数基本概念，结合经典目标的散射机理和雷达像分析，讨论复杂目标高分辨率雷达图像理解和对像素值的解释.研究表明:雷达图像的像素值不应直接解释为目标的RCS电平，但在空间频率域和图像域，两者数据之间满足帕萨瓦定理；在小孔径角成像条件下，空间频率域的RCS均值等于强度图像的全部像素值之和.     

A Monte Carlo study of the rough-sea-surface influence on the radarscattering from two-dimensional ships

The generalized forward-backward (GFB) method was introduced in Pino et al. (1999) for computing the electromagnetic scattering from two-dimensional targets on a rough surface. The GFB method is used in this article to generate numerical data for a Monte Carlo simulation of the horizontally polarized radar cross section (RCS) of two-dimensional ship-like targets on random rough sea surfaces. The RCS is computed as a function of the incidence angle and wind speed for a large number of surface realizations. It is found that the mean RCS of a given target on a rough surface is generally lower than or equal to the RCS of the same target on a flat surface, while the maximum RCS is usually greater than or equal to the flat-surface case. It is also observed that the variations in the RCS introduced by the rough surface become less significant as the elevation angle approaches grazing     

Low angle scattering from 2-D targets on a time-evolving sea surface

The results of a numerical investigation of the electromagnetic scattering from two-dimensional (2-D) targets on a time-evolving sea surface are presented. The 2-D radar cross section (RCS), or "echo width," is computed as a function of time as the sea surface evolves linearly using the spectrally accelerated generalized forward-backward method. It is shown that the RCS varies with time on the order of seconds, which is much longer than the typical pulse width or pulse repetition rate of search radars. It is also observed that for low-grazing angles of incidence the primary sea surface influence on the RCS comes from the long waves in the ocean spectrum.     

Application of geometric diffraction theory to scattering from cones and disks

The ability of the geometrical theory of diffraction to predict the radar cross section (RCS) of a perfectly conducting, right circular cone as a function of viewing angle is evaluated by comparison of computed and measured values of RCS. Both vertical and horizontal polarization have been considered for cones ranging from 0.98 to 2.87 wavelengths in diameter at the base and having half angles of 4°, 15°, and 90°; the latter case corresponds to a disk. It is shown that for cones having normalized base circumference (ka) of 8 or 9 the predicted and measured RCS agree very well except when the cone is observed within about 30° of nose-on with vertical polarization, in which case large errors occur for some as yet unknown reason. For smaller cones having diameters about equal to the wavelength (ka around 3), the computed RCS is generally predicted within 5 dB, but the form of the RCS pattern is not predicted very accurately. Backscattering from the base of the cone is very nearly the same as backscattering from a disk of the same diameter for viewing angles within 60° of the normal to the base.     

Structural–electrical coupling optimisation for radiating and scattering performances of active phased array antenna​

It is well known that calculating and reducing of radar cross section (RCS) of the active phased array antenna (APAA) are both difficult and complicated. It remains unresolved to balance the performance of the radiating and scattering when the RCS is reduced. Therefore, this paper develops a structure and scattering array factor coupling model of APAA based on the phase errors of radiated elements generated by structural distortion and installation error of the array. To obtain the optimal radiating and scattering performance, an integrated optimisation model is built to optimise the installation height of all the radiated elements in normal direction of the array, in which the particle swarm optimisation method is adopted and the gain loss and scattering array factor are selected as the fitness function. The simulation indicates that the proposed coupling model and integrated optimisation method can effectively decrease the RCS and that the necessary radiating performance can be simultaneously guaranteed, which demonstrate an important application value in engineering design and structural evaluation of APAA.     

Measuring radar cross section at short distance

Radar cross sections (RCS) must be measured at large distance. We exclude here the special near-field methods. The distance (R) must be so large that different RCS contributions are added in the same way as at infinite distance. This leads to the ruleR > 2D^{2}/lambdaif the target cross range is confined withinpm D/2and a phase error ofpi /4is tolerated. It is shown, however, that if the RCS is measured as a function of an angle and is low-pass filtered with a cut off period ofphi_{c}(radians), the distance requirement could be changed toR > 4Dphi^{-1}_{c}(1 - lambda/2phi_{c}D)). All RCS measurements at such distances give approximately the same result after low-pass filtering. We assume that a set of isotropic point scatterers, accurately describes the target.     

基于三角函数拟合的RCS序列进动周期估计

利用雷达反射截面(RCS)序列估计进动周期为弹道目标特征提取和识别的重要途径。弹道目标在进动时,回波RCS序列为非平稳的周期序列,常规Fourier变换方法和周期间相关类方法需要较长观测时间和较高数据率才能有效地估计RCS的周期,这对于有限的雷达资源来说是不可接受的。该文提出一种新的估计弹道目标RCS序列周期的方法,该方法先利用特定频率附近的三角函数来拟合RCS序列,再求得使拟合误差最小的频率,即为RCS序列的进动频率。相比于常规方法,该文方法具有所需资源少,估计精度高的特点。RCS计算数据的仿真结果证明了该文方法的有效性。