移动网络网元分布式部署研究

移动数据业务快速发展,移动宽带网络的投入成本和收入问题,对网络扁平化趋势下网元分布式部署提出了一定要求。本文在研究移动网络分布式部署驱动力的基础上,分析了各种移动网络分布式部署模型关联成本因素的影响,提出了部署策略。     

Disruption tolerant networking by Smart Caching

Future mobile radio networks will aim at achieving ‘broadband access for all’, anywhere. The performance of a radio network vitally depends on the characteristics of the transmission path between the user terminal and the access point and the degree of network coverage. In urban areas, full broadband radio coverage is difficult to provide, causing a high variation in the link quality and making broadband services hard to realize. In rural regions, massive deployment costs prevent a full broadband coverage. Most of the time users have to settle for UMTS‐like wide area networks. For mobile users accessing services, such as video streaming, which require continuous broadband connectivity, it virtually results in intermittent network connectivity. The frequent disruption of the broadband link and its replacement with no or only low‐performance connections is a problem that should be addressed. This article introduces a new technique called Smart Caching (SC), which is able to mitigate variations in the network performance so that non‐real‐time and non‐interactive services' quality is substantially improved. SC supports pre‐fetching from a server and buffering data at the edge of the core network, in the so‐called Smart Cache. It transmits data with extremely high speed to be buffered in the mobile terminal when it is in the service range of an access point. This allows for the provisioning of data‐intensive services even in the case of patchy wireless broadband network coverage and intermittent connectivity. The performance of the SC service is evaluated with two different sophisticated queuing models, both based on the Markov arrival process. The benefit of the new technique is discussed and dimensioning issues are outlined. Furthermore, a comparison with legacy network setups is given. Copyright © 2009 John Wiley & Sons, Ltd.     

Developing ecological index for identifying roles of ICT industries in mobile ecosystems: The inter-industry analysis approach

With the convergence of information and communication technology (ICT) industries in the mobile communication sectors, new actors have started emerging such as mobile contents and media service industries. The traditional distribution of power in ICT industries of mobile communication sectors has significantly changed based on relations with the new actors. Recently, the concept of a “mobile ecosystem” which embraces this environmental shift is highlighted. The traditional industries such as hardware and network-based firms and new ICT industries such as software and service-based firms grow up simultaneously creating the mobile ecosystem. In this respect, this study aims to explore ecological indexes for identifying roles of ICT industries in the mobile ecosystem. To be specific, the ecological indexes are proposed to take new roles and position of ICT industries in the perspective of ecosystem into account. For this, the inter-industry analysis, which includes the physical flows between industries, is mainly used since the ecosystem is operated by streamlining physical flows. First, the mobile ecosystem is structured by using physical input-output flows and industrial relationships. Second, to explore roles of ICT industries in the mobile ecosystem, four ecological indexes have been developed and combined based on the result of inter-industry analysis: productivity, size, spillover effect, and coverage. As a result, we identified six roles for ICT industries and their relationships: commodity, landlord, controller, keystone, facilitator, and dominator. Regarding these ecological roles and relationships in ICT industries, strategic and policy implications are also suggested to improve the health of the mobile ecosystem.     

基于多通道WIFI机顶盒的家庭无线宽带覆盖

基于广电CMTS接入网络提出多通道WiFi机顶盒创新方案解决家庭宽带盖问题,实现第三方网络运营商在广电网络中的通道租赁,达到多个运营商共用同一物理介质进行各自独立宽带运营的目的。该组网方案得到双方及其终端厂商认可,并证明其可行。     

一种适应小型网络向未来智能网络演进的方法

随着信息化时代的到来,宽带应用为关系国计民生的基础设施,但目前有线网络的宽带覆盖不够,缺少稳定的移动信号,区域之间的"信息化鸿沟"依然存在,为此提出一种针对地域广、用户基数少、通信质量差地区的全面提升网络质量、直接向5G演进、低成本易维护的网络架构模型。     

Does ICT promote democracy similarily in developed and developing countries? A linear and nonlinear panel threshold framework

This paper assesses the impact of ICT adoption on democracy for a panel of 70 countries over the period 2000–2017. We consider two different measures of ICT and check for the stability of the relationship for different levels of economic development. Our findings show that both internet and mobile technologies increase the level of democracy in our sample countries. When considering the level of economic development, divergent results are reported for developing and developed countries. Developing countries most commonly have autocratic political regimes where internet and mobile content is monitored by government authorities. More ICT diffusion produces in these cases a negative impact on their level of democracy. Moreover, these countries do not show any presence of a threshold of ICT use necessary to enhance their level of democracy. Our findings however report the presence of a nonlinear relationship in developed countries, suggesting that the effectiveness of ICT in enhancing democracy increases as more users are connected to ICT networks. Our findings also show that unlike developing countries, press freedom and ICT adoption are complementary in developed countries. That is, when developed countries are better endowed with ICT, they can enhance the freedom of their press and therefore their level of democracy.     

基于TD-LTE移动宽带技术解决农村区域无线宽带接入的应用

为在4G发展窗口期,有效解决农村区域4G覆盖范围内无线宽带的接入问题.采用TD-LTE (4G)移动宽带技术共模或Refarming模式利用现有频谱资源方式、同期配合辅助使用4×4 MIMO提升网络容量、差异化保障混合业务、M-CDN方案减少用户时延等方法解决农村区域宽带接入需求,保证网络的整体客户感知,合理利用资源,保证窗口期农村区域投资收益最大化.     

The Mobile Broadband WiMAX Standard [Standards in a Nutshell]

Mobile worldwide interoperability for microwave access (WiMAX) is a wireless standard that introduces orthogonal frequency division multiple access (OFDMA) and other key features to enable mobile broadband services at a vehicular speed of up to 120 km/h. WiMAX complements the and competes with wireless local area networks (WLANs) and the third generation (3G) wireless standards on coverage and data rate. More specifically, WiMAX supports a much larger coverage area than WLAN, does not require line of sight for a connection, and is significantly less costly compared to the current 3G cellular standards. Although the WiMAX standard supports both fixed and mobile broadband data services, the latter have a much larger market. Therefore, this article will briefly present the Mobile WiMAX standard, the technologies deployed for the air interface and the network, and the development of the standards to support mobile multihop relays in a WiMAX network.     

TD-SCDMA和WiMAX技术融合实现宽带无线移动通信系统

本文主要论述了基于TD-SCDMA和WiMAX技术融合实现一种新型的宽带无线移动通信系统。在该系统中,TD-SCDMA接入网提供广域无线覆盖,支持高移动性,提供话音业务和中、低速数据业务;WiMAX接入网提供热点区域覆盖,支持游牧移动性,提供高带宽流媒体数据服务,两种接入技术在网络层实现汇聚,通过网络层移动性管理技术,共享核心网络和业务系统,实现两种接入网的统一的无线资源管理以及统一的用户管理和计费,移动终端可以在该系统下的两种网络之间实现无缝漫游和切换。该种新型的移动通信系统能够很好的满足用户对移动通信业务的使用要求,也能够有力支持TD-SCDMA大规模独立组网,增强TD-SCDMA的竞争力;同时,也为TD-SCDMA系统的演进和跨越式发展提出新的思路。     

Why do people access news with mobile devices? Exploring the role of suitability perception and motives on mobile news use

Using self-reported survey data (N = 281), the present study explores the structural relationships among mobile users’ perceptions of the suitability of two types of mobile news (political feature news and entertainment news), users’ motivations for mobile news usage, and their behavioral patterns. Our findings show that two types of perceived suitability for mobile news, particularly for political feature news, are strongly associated with all dimensions of motivations for mobile news usage. Furthermore, as predicted, our findings show that the information-seeking motive is the very factor that determines mobile news usage. The results also reveal that the accessibility motive mediates the relationship between the perceived suitability of obtaining news via a mobile device and users’ mobile news behavior. However, contrary to our expectation, the social utility motive does not mediate the relationship between users’ perceptions of the suitability of mobile devices for this purpose and their mobile news usage. Finally, the information-seeking and accessibility motives each have an indirect effect on the association between perceived suitability and mobile news usage. The implications of the study and recommendations for future research are also discussed.     

WiMAX关键技术及网络结构探讨

WiMAX支持非视距传播条件下的无线宽带接入,它致力于为无线网络提供低时延、高质量的语音和数据服务,正迅速发展并将在无线城域网中扮演重要角色。WiMAX技术因其定位于城域级的无线宽带接入,具有覆盖范围广、传输距离远、传输速率快等优势,在未来的无线宽带移动通信领域将会占有相当重要的主导地位。文中从WiMAX的基本特征、关键技术和网络结构及应用3个维度对WiMAX进行了分析与探讨。     

多运营商高铁隧道移动网络覆盖方案

高铁移动网络覆盖是国内三大通信运营商的一个重点,而高铁隧道内移动网络覆盖更是运营商的一大难点痛点。文章根据我国中部省份某高铁线路覆盖规划实例,采用“设备+POI+泄漏电缆”模式,即三家运营商信号源设备通过同一POI(point of interface,多系统接入平台)接入,信号输出到泄漏电缆进行隧道覆盖,隧道口场坪站安装宽频切换天线对隧道外进行延伸覆盖,通过链路预算合理布置各运营商主设备信号源,从而实现隧道到室外的无缝覆盖。最后,根据已有成熟网络覆盖解决方案,对未来5G高铁隧道移动网络覆盖方案进行了探讨。     

ICT and environmental sustainability: A global perspective

The positive and negative environmental impacts of information and communication technologies (ICTs) are widely debated. In theory, ICT is among the sources contributing to the increasing levels of CO₂ emissions in terms of production of ICT machinery and devices, energy consumption, and recycling of electronic waste. However, ICT is also expected to reduce CO₂ emissions on a global scale by developing smarter cities, transportation systems, electrical grids, industrial processes, and energy saving gains. These two effects work in opposite direction, creating an inverted-U relationship between ICT and CO₂ emissions. The aim of this study is to investigate this non-linear relationship between ICT and CO₂ emissions on a global scale. Given that global warming is a global issue, it is necessary to look at this relationship in countries at all levels of development. To this end, we use a panel data set consisting of 142 economies, split into 116 developing and 26 developed countries, over the period 1995–2010. The results of our empirical study confirm that the relationship between ICT and CO₂ emissions is an inverted U-shaped relationship. Moreover, while for the sample of developing countries, the ICT turning point is well above the mean value, the opposite is true for the sample of developed countries. This implies that many developed countries have already attained the level of ICT development, at which CO₂ emissions decreases as the level of ICT development improves further.     

Analyzing the Economic Effects of Past Mobile Network Sharing Deals for Future Network Deployment

The increase in data traffic calls for investment in mobile networks; however, the saturating revenue of mobile broadband and increasing capital expenditure are discouraging mobile operators from investing in next-generation mobile networks. Mobile network sharing is a viable solution for operators and regulators to resolve this dilemma. This research uses a difference-in-differences analysis of 33 operators (including 11 control operators) to empirically evaluate the cost reduction effect of mobile network sharing. The results indicate a reduction in overall operating expenditure and short-term capital expenditure by national roaming. This finding implies that future technology and standards development should focus on flexible network operation and maintenance, energy efficiency, and maximizing economies of scale in radio access networks. Furthermore, mobile network sharing will become more viable and relevant in a 5G network deployment as spectrum bands are likely to increase the total cost of ownership of mobile networks and technical enablers will facilitate network sharing.     

小区有线宽带接入选点模型研究

本文从小区宽带接入技术的选择入手,研究家庭宽带产品的发展现状及面临的问题。分别从市场竞争、客户粘性、投资收益对现有网络的影响、接入难度等多个维度构建各类典型小区的接入选点评估模型。通过模型应用,可以有效解决移动运营商小区宽带接入选点问题。     

ICT expansion and the digital divide in democratic freedoms: An analysis of the impact of ICT expansion, education and ICT filtering on democracy

In recent years, several case studies have appeared on how mobile telephones, SMS and the Internet had an impact on political activities. It has been widely argued that information and communication technology (ICT) is influencing democracy all over the world. However, few studies provide any analysis of how ICT expansion correlates with measures of democracy. In this paper, we investigate the relationship between the global expansion of ICT and the level of democracy within nations. We analyze archival data on 133 countries from 1995 to 2003, which was the period-of-time of explosive ICT expansion. Some important findings of our study are: (a) there is a growing digital divide in democratic freedoms among countries; (b) in spite of rapid ICT expansion in some countries, Internet filtering is having a significant impact on democratic freedoms.     

Advancement of MIMO technology in WiMAX: from IEEE 802.16d/e/j to 802.16m

WiMAX is the first cellular standard that employs OFDMA technology and provides true integrated services for both fixed and mobile broadband access. Among the many new technologies adopted in WiMAX, MIMO antenna technology plays an essential role in delivering fast, rich-content, mobile broadband service reliably over extended coverage areas. In this article we provide a survey on the state of art of MIMO technologies in current WiMAX standards with an emphasis on practical engineering considerations. Moreover, we also briefly discuss the ongoing MIMO technologies in the evolution toward the next-generation WiMAX network.     

基于FTTx的下一代通信网精确覆盖系统的设计与实现

在"宽带中国"上升为国家战略的大背景下,有效支撑移动宽带和固定宽带业务的发展是当前及今后一段时期通信网络转型的一项重大举措,也是室内深度覆盖建设转型的契机。通过探讨基于FTTx的下一代通信网精确覆盖系统的设计、系统基本原理、硬件电路原理及系统硬件实现等方面,为各运营商在无线网室内精确覆盖方案的制定提供一定的参考。     

基于室内场景的多天线技术应用

多天线技术是无线接入网宽带化、高速化的关键技术,在4G移动通信系统中有着广阔的应用前景.室内覆盖是移动通信的主要业务,运用MIMO技术有效解决室内无线通信系统具有重要意义.围绕无线MIMO技术在室内覆盖中的运用这一主题,对MIMO信道容量、室内信道建模、室内覆盖系统等方面进行了深入的研究.