“三合一”设备在有线电视双向网络改造中的应用

张家港市于2006年完成有线电视“户户通”工程,并于2008年上半年完成有线数字电视整转工程,成为江苏省首批“有线数字电视户户通市”。2009年3月张家港广电信息网络有限公司着手有线电视网络双向改造,计划用2年时间,完成全市的有线电视网络双向改造工程,为双向业务的拓展奠定扎实的网络基础,截止2009年10月,已完成双向改造的光节点为825个,完成双向改造的网络可覆盖用户15万户,新增宽带用户5100户。     

电广传媒年底完成湖南有线网络整合

8月26日,电广传媒董秘办的工作人员接受记者采访时表示,在国家加快推进有线网络整合的精神指导下,公司有望在2009年底完成湖南省有线网络的整合工作。7月29日,国家广电总局出台《关于加快有线网络发展的若干意见》,要求各省2010年底之前完成省内有线网络的整合。当前,除了几个县市,电广传媒已经完成了对湖南省大部分有线网络用户的整合。但总部设在北京的中信国安,在长沙、岳阳等三个城市拥有有线电视网络,因此成为电广传媒完成湖南全省整合无法回避的问题。     

数字全业务OTN传输方案的设计与实现

南平广电要完成数字化平移,完成各县市整合,现有的网络仅勉强能够承载当前电视节目流,已无法满足未来业务发展的需求.本次OTN传输方案从南平网络现状需求及发展压力出发,结合对整体网络的考虑,通过业务的模型预测与网络规划来实现.     

EPS FB成功率优化策略研究

移动用户对5G网络的普遍期望高,认为5G网络速度快、覆盖好、体验优,然而在5G SA网络商用初期,在当前VoNR语音方案部署还不成熟的情况下,5G语音需要通过EPS FB技术将语音回落到LTE网络,通过VOLTE完成语音业务的连接,用户终端空闲态及数据业务态驻留在NR网络,当有语音业务请求时,终端由NR网络回落至LTE网络完成语音业务,用户完成语音业务后返回NR网络,因此对EPS FB语音策略专研,并制定相应的优化对策,是5G用户语音感知体验提升的重要保障。     

昆钢有线电视双向网络改造实践

1 双向网络改造模式 云南昆钢电视网络有限公司有近3万用户,数字整体平移已经完成,电视信号采用省广电网络统一数字电视信号,互动视频点播信号已由省机房送至昆钢机房,目前的任务是如何快速完成双向网络改造,尽快实现增值业务的发展。     

NGB与“三网融合”的关系

一NGB的理解与具体化 中国下一代广播电视网（NGB）的目标就是一个可以提供全业务,并且网络设备和运营业务可管可控的网络。当前的HFC网络只要完成了双向改造,就可以在HFC网络上提供IP电话业务、互联网上网业务,再加上HFC网络本身提供的电视业务,就实现了“三网融合”,因此我们可以认为完成了双向网改的HFC网络就是NGB网络。     

立足TD江苏移动积极引领竞争

1 保质保量完成TD-SCDMA网络建设任务 在时间紧、任务重、难点多的情况下,要加强协调,排除万难,确保完成南京地区所有网络建设和初步优化工作.同时,根据集团公司统一安排,启动全省TD_SCDMA网络建设.按照边建设、边维护、边优化的思路,同步做好网络维护和优化工作,不断提高TD-SCDMA网络质量.     

一种基于软交换的短波接入网关设计

为满足短波用户接入Internet网络中的要求,结合软交换的思想,设计了一种短波接入网关.主要通过tun/tap完成有线网数据的获取,通过协议代理完成不同链路之间的协议转换,通过对短波链路物理层设备的控制完成短波链路数据的交互.通过搭建室内平台,验证了短波网络与Intemet网络的联通性,以及与其他短波网关相比在功能上的优势.     

探究LTE网络中基于博弈论的资源分配及网络选择算法

主要研究LTE网络基于博弈论的资源分配与网络选择算法,建立了单个用户的效益模型和多用户的博弈模型,并利用进化博弈论完成群体网络决策优化,均衡多重网络负载,提高网络稳定性。     

WCDMA综合网管系统分析与设计

1引言 中国联通从2009年2月开始到2009年5月17日为WCDMA网络建设的第一阶段,完成了WCDMA试商用建设。从2009年5月17日到2009年9月底,进行WCDMA网络的大规模建设,完成了WCDMA商用的准备工作。从2009年10月开始,WCDMA网络正式商用。     

基于拨备满足模型的无线传感网节点覆盖算法

针对无线传感网预覆盖过程中存在覆盖盲区以及数据频繁重传而导致的节点覆盖抑制现象,提出了一种基于拨备满足模型的无线传感网网络覆盖算法。设计一种新的无线传感网节点覆盖模型,并构建覆盖指数、覆盖强度、覆盖均衡评估系数等评估维度,快速评估节点覆盖质量。再计算覆盖均衡评估系数,并采用拨备模型优化覆盖质量,确定覆盖性能优越的备用工作节点。随后,基于覆盖相似性原则评估工作节点覆盖性能,设计了节点首次覆盖评估方法,按节点移动路径依次评估覆盖指数统计均值,并根据目标节点进入覆盖区域的先后,逐次激活性能最佳的工作节点进行监测。仿真实验表明：与当前无线传感网常数节点覆盖方案相比,所提方案具有更高的网络覆盖率、更短的覆盖启动时间和更少的工作节点数目。     

Cell-coverage estimation based on duration outage criterion for CDMA cellular systems

Previous papers addressing coverage analysis for code-division multiple-access (CDMA) cellular networks have focused on cell expansion from soft handoff or estimation of cell coverage based on an instantaneous outage criterion. Instantaneous outage estimates of cell coverage are a worst case assessment in that the predicted coverage as a function of the number of users is necessarily smaller than the actual coverage. We present the theoretical framework for estimating reverse-link cell coverage based on a duration outage criterion. Our results show that coverage estimates based on duration outage are typically 15%-30% larger than coverage estimates based on instantaneous outage when the correlation distance of the large-scale shadowing environment is small. We compare our theoretical duration outage results of cell coverage with simulated results that considered various large-scale shadowing conditions as well as Rayleigh small-scale fading. The theoretical and simulated coverage results are found to be in very good agreement. The simulations confirm that the presented theoretical duration outage analyses provide accurate and realistic estimates of reverse-link CDMA cell coverage.     

Impact of Interference on Coverage in Wireless Sensor Networks

The quality of surveillance is dependent on the sensing coverage of a wireless sensor network. In the present paper, we examine how interference affects the coverage of a wireless sensor network. The coverage fraction and required number of sensors for randomly deployed and well-planned deployed wireless sensor networks in the presence of interferers are computed. The required number of sensors to achieve higher level of coverage increases drastically for randomly distributed sensor nodes where the interference effect is high. In the case of well-planned distributed sensor network, required sensors increases linearly as interference effects become more pronounced. Algorithms for computing the required number of sensors to obtain the desired level of coverage in the presence of non-uniform interference is presented. The simulation results suggest that the coverage per subregion and coverage per sensor approaches towards, the improvement achieved is constant. The sensor saving ratio is independent of the level of the desired coverage provided the coverage per subregion is larger than or equal to the coverage per sensor.     

一种考虑反向缝的全球低轨卫星通信系统的波束排布方法

针对全球低轨卫星通信系统的动态性引起的反向缝区域覆盖问题,采用辐射场到地球覆盖区的转换方法,仿真分析了单个卫星服务区为圆形、椭圆和矩形时的全球覆盖情况,并采用椭圆子波束排布对椭圆和矩形的卫星覆盖进行了分析。结果表明,在不增加波束个数的前提下,采用波导缝隙阵的长椭圆子波束,单个卫星矩形覆盖可以有效解决卫星反向缝区域无法完全覆盖的问题。通过对多星影响下的载干比统计方法进行分析,得出这种卫星波束排布方法满足卫星通信的要求,为低轨卫星的天线波束设计提供了理论参考。     

CDMA2000网络覆盖典型问题分析与优化

网络覆盖状况是衡量移动通信网络性能优劣的关键,CDMA2000网络的覆盖、容量和质量相互制约。在参与中国电信CDMA2000网络优化过程中,整理了部分与覆盖问题有关的案例,对网络覆盖中的典型问题之弱覆盖、越区覆盖、前反向链路不平衡及导频污染的现象、判断依据及优化方法进行了分析,并列举了相关实例,对从事网络优化工作者有一定的借鉴意义。     

一种带有可控动态参数的优化覆盖算法

能耗与覆盖问题是无线传感器网络研究领域的基本问题,也是一个重点问题。针对传感器节点所呈现的同构性特点,提出了一种带有可控动态参数的优化覆盖算法（OCCDP）。该算法首先给出了3节点联合覆盖时,最大无缝覆盖率的求解过程;其次,给出了在监测区域内存在传感器节点覆盖时,覆盖质量期望值求解方法以及与邻居节点进行覆盖比对时覆盖率的判定方法;当存在冗余覆盖时,给出了任意传感器节点处于冗余节点覆盖时的覆盖率的计算过程;最后,通过仿真实验与其他算法在覆盖质量和网络生存周期等方面进行对比,其性能指标平均提升了11.02%和13.27%,从而验证了提出算法的有效性和可行性。     

一种适合高层建筑密集区域覆盖的智能天线

本文提出了一种适合高层建筑密集区域覆盖的智能天线结构和覆盖方法.针对不同高度和宽度的高层建筑可调整该天线的垂直面和水平面波束宽度,获得良好的覆盖区域;业务波束会随着业务终端所处不同楼层位置赋形跟踪.经过仿真验证表明,该天线和方法适合高层建筑密集区域覆盖,有利于节约资金和有效保证网络的深度覆盖.     

k-out-of-n:G System Reliability With Imperfect Fault Coverage

Systems requiring very high levels of reliability, such as aircraft controls or spacecraft, often use redundancy to achieve their requirements. Reliability models for such redundant systems have been widely treated in the literature. These models describe k-out-of-n:G systems, where n is the number of components in the system, and k is the minimum number of components that must work if the overall system is to work. Most of this literature treats the perfect fault coverage case, meaning that the system is perfectly capable of detecting, isolating, and accommodating failures of the redundant elements. However, the probability of accomplishing these tasks, termed fault coverage, is frequently less than unity. Correct modeling of imperfect coverage is critical to the design of highly reliable systems. Even very high values of coverage, only slightly less than unity, will have a major impact on the overall system reliability when compared to the ideal system with perfect coverage. The appropriate coverage modeling approach depends on the system design architecture, particularly the technique(s) used to select among the redundant elements. This paper demonstrates how coverage effects can be computed, using both combinatorial, and recursive techniques, for four different coverage models: perfect fault coverage (PFC), element level coverage (ELC), fault level coverage (FLC), and one-on-one level coverage (OLC). The designation of PFC, ELC, FLC, and OLC to distinguish types of coverage modeling is suggested in this paper.     

A pragmatic approach to area coverage in hybrid wireless sensor networks

Success of Wireless Sensor Networks (WSN) largely depends on whether the deployed network can provide desired area coverage with acceptable network lifetime. This paper seeks to address the problem of determining the current coverage achieved by the non‐deterministic deployment of static sensor nodes and subsequently enhancing the coverage using mobile sensors. We identify three key elements that are critical for ensuring effective area coverage in Hybrid WSN: (i) determining the boundary of the target region and evaluating the area coverage (ii) locating coverage holes and maneuvering mobile nodes to fill these voids, and (iii) maintaining the desired coverage over the entire operational lifetime of the network. We propose a comprehensive solution that addresses all of the aforementioned aspects of the area coverage, called MAPC (mobility assisted probabilistic coverage). MAPC is a distributed protocol that operates in three distinct phases. The first phase identifies the boundary nodes using the geometric right‐hand rule. Next, the static nodes calculate the area coverage and identify coverage holes using a novel probabilistic coverage algorithm (PCA). PCA incorporates realistic sensing coverage model for range‐based sensors. The second phase of MAPC is responsible for navigating the mobile nodes to plug the coverage holes. We propose a set of coverage and energy‐aware variants of the basic virtual force algorithm (VFA). Finally, the third phase addresses the problem of coverage loss due to faulty and energy depleted nodes. We formulate this problem as an Integer Linear Program (ILP) and propose practical heuristic solutions that achieve similar performance as that of the optimal ILP solution. A guiding principle in our design process has been to ensure that the MAPC can be readily implemented in real‐world applications. We implemented the boundary detection and PCA algorithm (i.e., Phase I) of the MAPC protocol on off‐the‐shelf sensor nodes and results show that the MAPC can successfully identify boundary nodes and accurately determine the area coverage in the presence of real radio irregularities observed during the experiments. Extensive simulations were carried out to evaluate the complete MAPC protocol and the results demonstrate that MAPC can enhance and maintain the area coverage, while reducing the total energy consumption by up to 70% as compared with the basic VFA. Copyright © 2010 John Wiley & Sons, Ltd.     

NB-IoT网络与业务协同优化

现阶段NB-IoT网络已完成初步建设,整体覆盖较好,但局部覆盖空洞较多,室内疑难场景深度覆盖不足,干扰问题突出,重叠覆盖严重。目前NB-IoT行业应用成熟度低,行业应用属于起步阶段,各厂商终端规范不一,导致网络部署调通过程中存在较大问题。针对当前物联网的主要业务类型,依据不同业务特征来分析NB-IoT网络关联指标,根据测试数据与统计数据分析该类业务的覆盖性能,对井盖与灯杆类业务分别展开深度覆盖分析与重叠覆盖分析,对业务接入相对集中的业务模型给出优化解决方案。