Techno-economic evaluation of 3G and beyond mobile business alternatives

Three business case scenarios in the context of emerging mobile access network technologies and business players have been studied and the economical results are presented. The aim is to cover some of the most interesting business alternatives in providing the new 3G and beyond services including cases where the operator may have an existing second-generation cellular network or not, and a license for the 3G UMTS network or not. The scenarios have been analyzed in different Western European country groups that are not exactly representative of any defined country, but rather share typical demographic characteristics. Investments and operational expenditures are identified and the results show how diverse business models and technologies lead to different revenue, cost, and profitability profiles. The business case scenarios include incumbent’s 3G evolution with UMTS compared to an alternative 3G technology deployment with mobile WiMAX, new entrant’s UMTS deployment business case, and a greenfield CDMA450 deployment business case.     

Achieving low-cost UMTS networks via pricing

One of the main concerns of mobile operators towards deployment of Universal Mobile Telecommunications System (UMTS) networks is the investment cost. The costly radio access network, based on the network equipment required in a service area, prevents incumbents and new entrants from upgrading or building a new UMTS network. In this article, a novel, low-cost approach to the UMTS radio access network design is proposed. The approach employs the use of pricing incentives. This approach is based on the assumption that a pricing mechanism is in place to control excessive traffic load during peak periods. By incorporating this assumption into the network design, the network designer is able to relax certain design parameters, which may contribute to significant savings in equipment cost. Investigation is focused on the UMTS coverage and capacity planning, using the Net Present Value (NPV) financial analysis. For certain price-sensitivity levels, the analysis indicates that this approach provides a suitable strategy for mobile operators to comfortably move forward with UMTS upgrade and gain competitive edge in the wireless market.     

面向密集部署的超高吞吐率Wi-Fi融合应用技术

为了降低网络密集部署对超高吞吐率（VHT） Wi-Fi性能的影响,提出了VHT Wi-Fi基于软件定义网络（SDN）的网络架构、无线网络侧虚拟化和增强型认证与快速切换技术,以提高系统的共存性、抗干扰性和安全性。实验结果表明,VHT Wi-Fi与SDN、网络功能虚拟化、伽罗瓦/计数模式协议结合,吞吐率性能获得约10%的提升,在保证安全性同时平均切换时延降低至40 ms,可保障VHT Wi-Fi在密集部署网络中发挥重要作用。     

LEO星地Wi-Fi方案设计与验证

低轨（LEO）卫星到地面之间的无线保真(Wi-Fi)通信系统当前已经获得了广泛关注。针对LEO卫星信道的高误码、长时延等特点,采用导频插入、选择重传、帧聚合等方法对IEEE802.11g进行改进,并在开放式无线接入研究平台（WARP）v3上完成了改进方案的设计。对改进后方案的多普勒频偏性能、远距离传输速率以及高速移动条件下的传输速率等系统性能进行测试的结果表明,改进后方案在复杂信道环境下可以获得比商业Wi-Fi更好的系统性能。通过模拟验证改进方案的系统性能,证明了基于LEO卫星的Wi-Fi卫星通信系统的可实现性。     

Techno-economics for multi-service fixed access networks

The paper presents techno-economic results for fixed access networks which have been achieved within the IST MUSE (Multi Service Access Everywhere; http://www.ist-muse.org) integrated project in the first phase. The article summarises the results from studies of two major use cases, Network Migration Cases and the Native Ethernet approach. The results are based on a common framework. A specific attention is paid to the first mile deployment scenarios including Fibre to the Cabinet (FTTCab) and Point-to-Point optical networks (PtP). It has been observed that the migration from a best effort access network to a Quality of Service (QoS) enabled multi-service architecture based on Ethernet or IP forwarding is favourable in comparison with an ATM-based evolution scenario. Service enabling new network functionalities like Quality of Service (QoS), multicast and Internet (IP) based auto-configurations are moving closer to subscribers. This leads to an increased intelligence in access networks and related potential Capital Expenditures (CAPEX) savings of about 25% in aggregation networks.     

采用部分频率复用的小小区网络建模与分析

小小区组网技术被认为是解决迅速增长的移动数据量需求的方法。然而,密集的小小区组网会导致严重的小区间干扰。传统的部分频率复用方法不能完全照搬用在部署不规则的小小区网络内,急需一种合理高效建模采用频率复用小小区网络的方法,对其性能进行评估。利用随机几何理论对小小区网络考虑部分频率复用场景进行建模,推导了考虑部分频率复用的小小区网络下行覆盖概率和网络吞吐量的表达式。数值仿真结果显示:部分频率复用技术可以提高小小区网络下行覆盖概率,但是会降低网络图吞吐量。在满足覆盖概率约束条件下,得到了使得网络吞吐量最大的频率复用因子的表达式。以上结果对未来采用频率复用技术的小小区组网的具体实施具有重要的指导意义。     

SCTP在无线网络上的最佳协议参数配置分析

本文研究了在WLAN、GPRS、UMTS这3种无线网络上运行流控制传输协议(SCTP)时,不同的协议参数配置对系统传输性能的影响。文中找出了达到最大系统传输性能时的SCTP协议参数设置,从而解决了符合IETF-RFC2960的SCTP应用于无线网络上协议最佳参数选择的关键问题。理论分析和仿真结果表明,运行于无线网络上时,采用了最佳参数配置的SCTP协议传输性能明显地高于采用传统参数配置的SCTP协议。     

The Effects of Food Color on Perceived Flavor: A Factorial Investigation in India

We extend research testing the effects of food color on flavor to a new cultural setting—India. We test color’s effect at three levels: flavor identification, perception, and preference. One hundred twenty-two graduate students at an Indian business school enrolling students from all parts of India were assigned the task of tasting and evaluating an orange-flavored carbonated water. Color at two levels (purple and orange) and label information at two levels (told orange flavor, told grape) were manipulated in a full factorial, between-subjects design. Results confirm that food color affects the consumer’s ability to correctly identify flavor as well as to form distinct flavor profiles and preferences. Food color dominates other flavor information including labeling and taste, though the strength of the effect is less pronounced in this setting. Strategic alternatives for the effective deployment of food color for promotional purposes are recommended.     

晚年独居意味着孤独吗?——基于社会网络的调节与中介作用分析

老年人独居比例和孤独感的上升已经成为家庭现代化转型中的典型现象,现有对二者关系的研究忽视了社会网络的视角。基于2014年中国老年健康影响因素跟踪调查数据,利用潜在类别分析和logistic回归模型考察了社会网络在老年人独居和孤独感之间所发挥的作用。研究发现,老年人独居并不意味着会感到孤独,不同类型的社会网络加重或缓解了独居带来的孤独感上升。具体而言:第一,老年人社会网络可以分为多元-活跃型、社会-消极型、子女-消极型和单一-活跃型四种类型;资源禀赋丰富的老年人具有多元-活跃型社会网络的概率更大。第二,仅具有子女-消极型社会网络的老年人,单人独居才会显著提升他们的孤独感。第三,单人独居和夫妇独居老年人均会通过多元-活跃型的社会网络缓解自身孤独感。应通过积极的公共政策,从能力建设和社区环境营造两方面,推动老年人社会网络向多元-活跃型转变。     

行星表面有人探索高速无线网络体系架构及关键技术

针对行星表面有人探索任务对高速无线通信的需求，提出了一种基于异构组网思想的网络体系架构，并对关键技术进行了分析和设计。该架构采用“三网两体制”的设计思路，将整个网络分为高速传输网、多媒体接入网、覆盖扩展网三个组成部分，三层网络分别完成高速骨干传输、多节点多业务接入、覆盖范围灵活改变的功能。根据三个网络不同的节点处理能力和传输需要，设计了高速传输体制、灵活接入体制两种传输体制，及基于无线多跳的覆盖扩展技术、多子网通信切换技术、多体制融合技术等关键技术。该网络架构具有裁剪灵活、协议开销小、支持业务类型多等特点。     

Effects of knowledge types on choice quality and perceptions of choice performance

Two types of knowledge used in making choices are examined: knowledge of product-specific information and knowledge of a choice strategy. Product-specific information comprises information about available alternatives, including features and their importance. Strategy information includes knowing an appropriate strategy for integrating and evaluating information about alternatives, as well as knowing how to implement the strategy. The effects of these knowledge types, both singly and jointly, upon choice quality and perceptions of choice quality are examined in two studies. The results of the first study indicate that the knowledge types are differentially beneficial, and that subjects tend to be more overconfident about the perceived quality of their choices when they have product-specific information than when they have choice strategy information. The hypothesis that this difference is due to subjects' greater awareness of produce-specific information, rather than strategy information, is examined and supported in the second study. Implications for marketing and public policy are discussed. © 1996 John Wiley & Sons, Inc.     

自适应无线传输技术在高速下行数据分组接入中的应用

随着高速、多媒体数据业务需求的日益增长 ,未来无线移动通信系统越来越需要解决支持更高速数据传输技术及频带利用率的问题 ,自适应传输技术是提高频带利用率的有效手段。结合最新3GPP提出的高速下行数据分组接入HSDPA ,归纳、总结和分析了自适应无线传输技术在HSDPA的应用以及其优点和应用前景、未来的研究方向     

Modeling and Forecasting the Sales of Technology Products

Managers in technology product markets require sales response models that provide substantive insights into the effects of marketing activities as well as reliable sales forecasts. Such markets are characterized by frequent introductions and withdrawals of multiple models by different companies. Thus, the data available on the performance of any individual model is scarce. A second characteristic is that the effects of product attributes and marketing activities could change over time as different types of consumers participate in the market at different points in time. Given sparse data, it becomes critical to specify a model that allows pooling of information across brand-models while at the same time providing brand-model specific parameters. We accomplish this via a hierarchical Bayesian model specification. Further, to capture the effects of changing consumer preferences over time, we specify a time varying parameter model. Our modeling framework therefore, integrates a hierarchical Bayesian model within a time varying parameter framework to develop a dynamic hierarchical Bayesian model. We employ data on digital cameras in the U.S. market to estimate the parameters of our proposed model. We use thirty-three months of national level data on the digital camera market with the data series beginning very close to the inception of this product category. We find that while there is little variation in reliance of benefits by early adopters, the second wave of adopters focus on Ease of Use followed by later adopters who rely on Storage and Image Quality. Looking at the elasticities of demand with respect to the various benefits, we find that at around the halfway point of our data series, the industry as a whole would have been better off investing in increasing image quality rather than storage if costs associated with the two are equal. However, at the end of the time horizon both benefits appear to have about equal impact. Further, the relative benefits of improving these attributes vary across brands and points in time. We then generate single period and multiple period ahead sales forecasts. We make different assumptions about information availability and find that the average (across brand-models and time) MAPE ranges from 7.5 to 14.5% for the model. We provide extensive comparisons of our model with 4 potential alternatives and find that our model outperforms these alternatives on the nature of substantive insights obtained as well as in forecasting out-of-sample especially when there is a very short time window of data.     

Value of digital information networks: a holonic framework

The worldwide extraordinary level of interest in digital information networks’ deployment among nations is due to the strong perception that they bring economic, social and environmental value. Our literature review on studies aiming at clarifying the value of information networks, led us to conclude that these studies take speculative, elusive or limited conclusions. We identify the requirements to capture the value of information networks and indicate a possible theoretical ground to account for it. Based upon this, we propose a framework operationalized with data from Eurostat. Furthermore, we identify the added-value of our framework with a precise and comprehensive comparison with two state of the art reference frameworks. We demonstrate that our framework provides significant conceptual added-value and, more fundamentally, allows for traditional measures of economic value (e.g. productivity and growth), as well as for other measures of value (e.g. social and environmental). Finally, we demonstrate with examples the wider application range of our framework in comparison with existing work.     

适用于3GPP信道的可重构天线设计

针对密集用户区高效宽带覆盖核心应用的电磁环境和业务需求，利用开关选择电路和表面贴 装技术，设计了支持选择功能的两单元天线系 统。该天线系统能完全覆盖UMTS(Universal Mobile Telecommunications System)频段。通 过对两天线系统方向图的测试，证明了两单元天线在空间能保持基本互补，且具有较高的稳 定性。     

Firm networks and firm development: The role of the relational mix

This study examines the role of different networks, called the relational mix, on the development of the entrepreneurial firm. Our regression analysis of survey data from 60 venture capital-financed firms questions the importance of network size on firm development. Rather, our results suggest that different types of networks are more important for firm development. In particular, we found a significant positive relationship for reputational networks and a weak significant negative relationship for cooperative technology networks at founding with time-to-break-even. Social networks at founding have no direct effect on time-to-break-even and a significant negative relationship with sales in the years after foundation. Furthermore, our findings show the important role of marketing information and co-opetition networks (relationships with direct competitors) on firm development in the years after foundation. These results suggest that the relational mix is a more appropriate construct for explaining network development than network size alone.     

GPRS与UMTS系统网络接入安全机制的比较与研究

详细介绍了GPRS与UMTS系统的网络接入安全机制，分析了GPRS系统中存在的安全漏洞及UMTS较GPRS在网络接入安全性方面的改善，最后分析了UMTS系统中存在的安全缺陷。     

Using stated response choice data to enrich revealed preference discrete choice models

There is growing interest in exploring the view that both revealed preference (RP) and stated preference (SP) data have useful information and that their integration will enrich the overall explanatory power of RP choice models. These two types of data have been independently used in the estimation of a wide variety of discrete choice applications in marketing. In order to combine the two data sources, each with independent choice outcomes, allowance must be made for their different scaling properties. The approach uses a full information maximum likelihood estimation procedure of the hierarchical logit form to obtain suitable scaling parameters to make one or more data sets comparable. We illustrate the advantages of the dual data strategy by comparing the results with those obtained from models estimated independently with RP and SP data. Data collected as part of a study of high speed rail is used to estimate a set of illustrative mode choice models.     

Neural networks in strategic marketing: exploring the possibilities

A review of the literature indicates that few studies have used artificial neural networks (ANNs) for data analysis in business and marketing research, even though there are many benefits to the use of ANNs. Therefore, this article discusses neural networks (NNs) that can be used in addition to or as an alternative to linear regression for data analysis in strategic marketing. The function and layout of NNs make them ideal for research dealing with nonlinear, incomplete, unspecified, or ‘fuzzy’ data and offer several advantages over linear regression. Unfortunately, in many marketing studies, the information being modeled is far from flawless and is often riddled with ambiguities linear regression is insufficient to accurately assess. NNs could be employed for great benefit by researchers analyzing the nonlinear, complex relationships in business data. The article discusses examples of types of studies that could be strengthened or expanded from neural network use.     

Yours,mine, and ours: A user-centric analysis of opportunities and challenges in peer-to-peer asset sharing

The sharing economy is growing globally in terms of user numbers, service providers, and novel concepts. Peer-to-peer (P2P) asset sharing, or asset rental between private individuals, has attracted the attention of entrepreneurs and researchers alike. P2P asset-sharing networks need to focus on two distinct customer groups: (1) asset owners willing to rent out their assets, and (2) renters interested in renting others’ assets. Despite consumers’ high interest in P2P asset sharing, participation rates lag projections, which is mainly attributable to lack of participating asset owners. This could be problematic for P2P networks as they do not own assets; instead, they rely on a sufficient number of asset owners to participate. Detailed indications on the participation motives of users are required to distinctly position P2P asset sharing and enhance communication of consumer-relevant benefits. To this end, we have engaged in a detailed investigation of participation motives in the P2P car-sharing context. We have conducted in-depth interviews with car owners and renters to derive usage types that represent consumer decision profiles that participate in P2P car-sharing services. Based on our findings, we provide extensive recommendations to entrepreneurs in the P2P asset-sharing market.