“非4G客户”不转4G网络的原因分析

本文通过整合中山市400万在网客户大数据资源,从用户分布、投诉热点、网络现状、用户流量等多维角度开展数据建模分析,并结合SQL数据库等大数据分析挖掘手段,基于网络投诉来分析非4G客户不转4G的痛点原因。从技术层面深度挖掘准4G用户在消费感知中遇到的问题,并以此快速定位需要针对性营销的目标用户,通过主动回访关怀或改善网络覆盖,从而提升用户感知,提升用户对移动4G网络的信心。实现市场网络一体化协同推广4G网络,促使非4G用户使用移动4G网络。     

3G和WLAN集成网络中的QoS的研究

将WLAN和3G结合,已经成为一种趋势.因此,需要考虑WLAN和3G结合的QoS问题.在这篇论文中,主要研究了将3G和802.11e相结合,为WLAN和3G集成网络的用户提供端到端的QoS业务.通过仿真,研究了WLAN误码率对3G业务类别传输吞吐量的影响.     

Linear time encoding of cycle GF(2/sup p/) codes through graph analysis

In this letter, we present a linear-complexity encoding algorithm for any cycle GF(2/sup P/) code C/sub E/(G,H). We just need to investigate the case where G is a nontrivial connected graph. If G is a tree, the only codeword is the all-zero word. If G is not a tree, first, we show that through graph analysis H can be transformed into an equivalent block-diagonal upper-triangular form simply by permuting the rows and columns of H; then, we show that whether H is full row-rank or not, the code can be encoded in linear time.     

High Altitude Aeronautical Platform for VoIP: Dependability Analysis

VoIP has become a revolutionary technology in the field of communication as it provides long distant calls at a very low cost and has many other advantages. But it depends upon a reliable Internet connection with high bandwidth availability. To meet this requirement researchers have proposed the employment of VoIP over 5G network (Vo5G) which is expected to upgrade mobile broadband services in future. In this paper, we recommend integration of Vo5G with high altitude aeronautical platforms (HAAPs) which are used to decrease the distance of transmitted signals from the satellites. HAAPs are also used to extend the coverage and capacity of wireless communication. We propose an architecture in which voice services will be provided through a 5G network which is integrated with HAAP, i.e., Vo5G integrated with HAAP. A dependability model is developed using the key components of Vo5G and HAAP to analyze the dependability attributes of the proposed architecture. To analyze the dependability model we use a semi-Markov process (SMP), a generalized version of continuous time Markov chain (CTMC), which takes into account the non-Markovian behaviour of the time spent in different states of the system. The steady-state as well as the transient results for availability and reliability are obtained through the SMP model. The steady-state results are obtained analytically, whereas the transient results are obtained through simulation. A comparison is also presented between Vo5G integrated with HAAP and Vo5G without HAAP to show that the former performs better. Numerical results are presented graphically, and the proposed dependability model is also validated through discrete-event simulation.

     

3G的传输需求和应对策略研究

3G代表了未来移动通信的发展走向,是移动业务发展的必然趋势,因此在目前建设传输网络时充分考虑3G系统的传输需求是十分必要的.本文针对目前业界在3G传输方面所存在的三大认识误区,分别从3G传输组网的特点、3G接入网络设备的功能和接口类型对传输组网的需求等方面的分析出发,并结合RNC和Node B接口的使用方法和新型城域传送技术的应用,剖析了3G的传输需求并研究了应对策略.     

Broadband penetration and economic growth: Do policies matter?

Although a significant body of literature has examined the interlinkage between broadband penetration and economic growth, the linkage between broadband policies and broadband penetration has been less studied in the literature. In addition, the role of 3G/4G services has also received limited attention. To address this issue, we combine the staggered timing of the implementation of broadband and 3G/4G services across countries and examine its impact on broadband penetration. Relatedly, we also examine the impact of broadband penetration on economic growth and the possible growth drivers. We find that while broadband policies improve fixed broadband penetration, 3G/4G services improve mobile broadband penetration; the magnitude of the latter being nearly three-times that of the former. Besides, we also uncover a positive effect of broadband penetration on economic growth, primarily working through a reduction in broadband prices and well as greater innovation and entrepreneurial activity.     

3G与WLAN的网络融合

随着3G移动通信应用业务不断丰富,通信网络的承载能力与大流量高宽带的业务需求之间的矛盾日益增加。3G技术难以支撑大量的数据用户的多媒体应用的需求。WLAN作为具有高性价比和大规模部署能力的无线数据技术,可以很好地卸载3G的压力。所以3G＋WLAN互为补充的发展战略成为运营商的共同选择。本文回顾了多种3G和WLAN相结合...     

密集城区基站最佳间距的Monte-Carlo仿真分析

在实际建设过程中,3G网络的自干扰、多业务特性使得网络性能之间的关联性远比2G网络复杂.网络规划需要借助规划工具通过各种模型的仿真预测网络性能.主要通过调整基站的方向角、下倾角,传播模型,对密集城区不同的基站间距进行Monte-Carlo仿真分析,得到最优的基站间距,对后期基站建设方案提供了参考依据.     

基于3G的SAR图像数据实时传输研究

根据SAR实时传输要求,从实际数据传输速率、成本等方面对我国现行的3种3G标准进行了对比分析,指出3种标准各有优缺点,TD的理论传输速率不如CDMA2000和WCDMA,但实际的应用中并不一定落后,而WCD-MA需要重新建立接入网,升级成本高,TD和CDMA2000则最大限度利用了已成熟的技术,演进成本低。要实现SAR图像数据的3G实时传输,要根据具体雷达数据量、SAR系统所处位置及各网络提供商的传输能力来定。     

基于可视化搜索技术的新一代3G移动电子商务

论述了可视化搜索技术的基本原理及其在3G互联网电子商务中的应用。通过把可视化搜索技术与3G电子商务结合起来,形成崭新的移动可视化电子商务模式,该模式利用了3G网络的优点,同时也充分利用了手机及其摄像头这一信息获取方式,是对传统无线电子商务的突破性扩展。     

ICAM: integrated cellular and ad hoc multicast

In third generation (3G) wireless data networks, multicast throughput decreases with the increase in multicast group size, since a conservative strategy for the base station is to use the lowest data rate of all the receivers so that the receiver with the worst downlink channel condition can decode the transmission correctly. This paper proposes ICAM, integrated cellular and ad hoc multicast, to increase 3G multicast throughput through opportunistic use of ad hoc relays. In ICAM, a 3G base station delivers packets to proxy mobile devices with better 3G channel quality. The proxy then forwards the packets to the receivers through an IEEE 802.11-based ad hoc network. In this paper, we first propose a localized greedy algorithm that discovers for each multicast receiver the proxy with the highest 3G downlink channel rate. We discover that due to capacity limitations and interference of the ad hoc relay network, maximizing the 3G downlink data rate of each multicast receiver's proxy does not lead to maximum throughput for the multicast group. We then show that the optimal ICAM problem is NP-hard, and derive a polynomial-time 4-approximation algorithm for the construction of the multicast forest. This bound holds when the underlying wireless MAC supports broadcast or unicast, single rate or multiple rates (4(1 + /spl isin/) approximation scheme for the latter), and even when there are multiple simultaneous multicast sessions. Through both analysis and simulations, we show that our algorithms achieve throughput gains up to 840 percent for 3G downlink multicast with modest overhead on the 3G uplink.     

浅析5G移动通信的关键技术及发展

【】2017年,全球多家移动通信企业宣布将共同支持加速5G新空口(5G NR)标准化进程,以推动于2019年尽早实现5G新空口的大规模试验和部署。为相应5G部署号召,现积极开展5G专题研究。通过简要回顾4G通信系统的兴起,引出5G概念并对其关键技术进行总结分析,同时对比4G与5G在指标能力上、技术对比上及应用场景上的差异,从而预估未来5G网络的发展方向。希望通过对5G移动通信若干关键技术浅析和与4G的差异化对比的探讨,为移动通信人员提供一些可行性的基础。     

2G/3G移动网络共传输方法与RNC配置

当前,中国已进入了第二代手机通信技术规格（2G）与第三代移动通信技术（3G）移动网络共存的时代,在2G/3G双代移动网络中,同一运营商有时为了节省传输资源,加快网络的部署,移动运营商可通过2G/3G网络共传输的方法来承载对应的3G/2G移动业务。2G传输系统承载3G业务可通过Fractional功能实现,具体实施是通过在RNC上输入命令ADD FRALNK。3G传输系统承载2G业务可通过建立CES电路仿真功能实现,具体实施是通过在RNC上输入命令ADD UDTCES命令实现。并以华为RNC设备为例分别介绍了2G/3G共传输具体实现方法。     

A new model for service and application convergence in B3G/4G networks

4G mobile communication networks encompass heterogeneous technologies that can be categorized at different levels according to their access coverage. Personal area, body area, and ad hoc networks are defined at a personal level, WLAN and UWB are examples at a local/ home level, and 3G technologies such as UMTS are technologies at a cellular level. In spite of their heterogeneity, these technologies shall be seamlessly integrated in 4G networks, naturally creating an open architecture. By openness we mean that the network architecture is divided into different layers, and the communication between these layers is performed through open interfaces or APIs. Although this open integration between 4G technologies is normally presented at the lower layers (connectivity and control), integration at the upper layers (service and application) is equally important. In this article we present a new model for service and application integration in 4G networks. This model generalizes the different service and application creation environments defined for each of the previously mentioned technologies, providing a uniform and interoperable framework for 4G services and applications. The model is based on a hierarchical architecture that provides compatibility for services in different technologies and at the same time is able to capture the specific details for each particular technology. The model also defines how 4G applications should be specified. In the last part of this article we present a testbed we have implemented in order to validate this model.     

A tutorial on multiple access technologies for beyond 3G mobile networks

In this article, some fundamental technical concepts of the main multiple access schemes for wireless mobile systems are reviewed, and a path for the development of appropriate multiple access technologies for next-generation mobile networks, or so-called beyond 3G (B3G), is established. We first review the multiple access technologies in second- and third-generation wireless cellular systems from historical and technical points of view. This review is followed by a novel formulization of the multiple access schemes through mathematical expressions that could simplify the process of development of new multiple access schemes for B3G wireless cellular systems. We then list the most important features of multiple access schemes in 3G mobile systems. Finally, we conclude the article by reviewing the most promising multiple access technologies for B3G mobile cellular systems     

Denial of Service Prevention for 5G

5G wireless mobile communication is expected to include a large number of advanced technologies in order to further increase bandwidth, Quality of Service (QoS), improve usability and security, decrease delays and cost of service. Software Defined Radio (SDR) will be the platform for advanced terminals. Our focus is security and especially prevention of Denial of Service (DoS) attacks which we believe will become more common in commercial networks through increasing availability of easy programmable SDRs. We propose a secret version of Adaptive Frequency Hopping, as a possible 5G technology in combination with others, with QoS estimation by means of physical layer parameters. The QoS parameter chosen is Bit Error Rate (BER) and this we use for blacklisting frequencies that we assume are under DoS attack. Our experimental results on BER estimation show this to be a promising approach.     

基于ARM+DSP的4G北斗定位平台的设计

针对如何提高北斗导航系统终端定位精度问题,提出了一种基于ARM+DSP架构并通过4G信号显示地图的北斗定位平台。其中DSP用来接收UM220-III发送的北斗信号,并使用无迹卡尔曼滤波算法修正定位结果;ARM接收DSP处理后的定位数据,通过嵌入式QT程序显示定位信息,当有4G信号覆盖时传至嵌入式BOA服务器上,调用百度API函数显示网络地图,当无4 G信号覆盖时通过mitab库调用.mif文件显示本地地图。经实验证明,本设计达到了提升北斗终端定位精度的要求。     

On the resolution of the mechanism for reverse gate leakage in AlGaN/GaN HEMTs

We provide following important clues for resolving the reverse gate leakage mechanism in AlGaN/GaN high-electron mobility transistors (HEMTs), based on two-dimensional (2-D) simulation and analysis. First, measurement of the gate current-voltage, I/sub G/-V/sub G/, characteristics on devices having different gate structures, passivation layers and interface charges, can reveal the field sensitivity of this mechanism. Second, of the different mechanisms proposed so far, namely - direct tunneling (DT), direct tunneling through a thin surface barrier (DTTSB) and trap-assisted tunneling (TT), DT/DTTSB is sensitive to the 2-D field, while the TT is not. Finally, the DT/DTTSB mechanism appears unlikely, since its 2-D calculations fit the measured I/sub G/-V/sub G/ shape, only if we assume a physically unrealistic voltage-variable charge at the interface and/or the TSB layer.     

A minimum-energy path-preserving topology-control algorithm

The topology of a wireless multihop network can be controlled by varying the transmission power at each node. It is not energy efficient to use the communication network G/sub max/ where every node transmits with maximum power. For energy efficient operations, it is desirable to have a subnetwork that preserves a minimum-energy path between every pair of nodes (where a minimum-energy path is one that allows messages to be transmitted with a minimum use of energy). We first identify conditions that are necessary and sufficient for a subnetwork G of G/sub max/ to preserve this property. Using this characterization, we then propose an efficient topology-control algorithm that, given a communication network G/sub max/, computes a subnetwork G that it preserves at least one minimum-energy path between every pair of nodes. We also propose an energy-efficient reconfiguration protocol that maintains this minimum-energy path property as the network topology changes dynamically. We demonstrate the performance improvements of our algorithm over other existing topology-control algorithms through simulation.