Forecasting category sales and market share for wireless telephone subscribers: a combined approach

The ability to forecast market share remains a challenge for many managers especially in dynamic markets, such as the telecommunications sector. In order to accommodate the unique dynamic characteristics of the telecommunications market, we use a multi-component model, called MSHARE. Our method involves a two-phase process. The first phase consists of three components: a projection method, a ring down survey methodology and a purchase intentions survey. The predictions from these components are combined to forecast category sales for the wireless subscribers market. In the second phase, market shares for the various brands are generated using the forecast of the number of subscribers that are obtained in Phase 1 and the share predictions from the ring down methodology. The proposed methodology produces the minimum Relative Absolute Error for each market as compared to the forecasts from each individual component in the first phase. The value of the proposed model is illustrated by its application to a real world scenario. The managerial implications of the proposed model are also discussed.     

The phoneless in the broadband age: A pilot study in Massachusetts

Questions about universal service continue to evolve as information and communication technology advances, bringing new platforms, services, and business models. Concerns about exclusion remain, particularly in times of transition to new technologies and platforms. While the universal service literature is rich in econometric studies that indicate the drivers of household telephone penetration, without qualitative data directly from those households that experience phonelessness, we cannot understand the causes well enough to design effective policy. This research explores why people are phoneless in the current environment of increased platform and business model choices. Particular focus is placed on understanding the relationship between new technology, platforms and business models and phonelessness. Data is obtained from surveys completed by approximately 100 individuals in Massachusetts who are currently without any voice connection, either landline or mobile, or have been sometime in the past ten years. The survey includes questions about different platforms and communication services in order to learn how they have led to phonelessness. The results of the pilot study show that the vast majority of phoneless households do not choose to be phoneless. The study also shows that the most frequent causes of phonelessness in this population are unemployment and unpredictable bills. Many instances of unpredictable bills leading to phonelessness occur with wireless service or bundled services but are the result of business models for service provision rather than the platforms themselves. Prepaid wireless service is a market-based solution that helps households prevent phonelessness by reducing unpredictability. Universal service policy for voice and broadband can better reduce exclusion with greater attention to business models and practices versus technologies and platforms, and increased emphasis on prepaid service to reduce unpredictability.     

相关瑞利衰落信道下空时分组编码性能分析

目前对空时编码的研究大都是基于信道是独立的假设下进行的,然而在实际系统中独立性假设是不成立的。基于此,研究了信道的相关性对空时编码性能的影响。计算机仿真结果表明：由于衰落信道的相关性,系统性能有所下降,且系统性能关于相关系数存在“地板效应”,即相关系数小于某一数值时,对系统性能的影响较小;当大于此值时,系统性能就会急剧下降。     

Investment decisions in the wireless industry applying real options

The wireless industry is one of the most capital intensive high-technology industries. This paper applies real options techniques to estimate investments under uncertainty in two new ventures: (a) deferral of the expansion from 2.5G to 3G networks; and (b) expansion of a 2.5G network using Wi-Fi as an alternative technology. The cases are examined and analyzed both qualitatively and quantitatively, using realistic assumptions and parameters. Investment cost, number of subscribers, pricing of services, and risk are at the core of investment decision processing. In both cases, sensitivity analysis of the value of the (real) option considering the above key parameters was conducted, to extrapolate useful findings that should be taken into consideration by the decision makers in wireless companies.     

无线局域网的现状及前景展望

无线局域网技术(包括IEEE802.11、蓝牙技术、HomeRF等)将是新世纪无线通信领域最有良好发展前景的重大技术之一。文中着重介绍了无线局域网标准的进展,IEEE802.11、蓝牙技术、HomeRF等几种主流标准的比较,分析了无线局域网技术、现状、局限与应用前景。     

一种无人值守接力的靶场安控系统

本文论述了中国实行对外开放是邓小平和中国人民把握历史和时代发展规律作出的战略抉择并取得了巨大成就;分析总结了中国入世前对外开放的基本特征及其原因;重点探讨了中国入世后对外开放的新阶段、新特点及其应对措施,推动对外开放新阶段和开放型经济新发展。     

POCSAG码的接收与软件译码方法

本文及时追踪世界物流产业发展中出现的第四方物流现象,论述了加入WTO后中国物流产业所面临的严峻形势——跨国公司意图垄断中国的第四方物流市场,而后提出了应对策略。     

The business case of a network that serves both public safety and commercial subscribers

Deploying a single nationwide broadband wireless network to serve all public safety users would have great advantages over the existing fragmented public safety systems. A nationwide system could be created to serve both public safety and commercial subscribers, which would allow a provider to exploit important economies but force it to meet the more costly requirements of public safety. This paper analyzes the viability of a public-private partnership that serves public safety and commercial subscribers from a for-profit provider's perspective. A model is presented that estimates the net present value (NPV) of a wireless network by calculating costs based on the number of cell sites required and revenue based on the projected number of subscribers acquired. The model is applied to both a network that serves only commercial subscribers on 10 MHz of 700 MHz spectrum and a public-private partnership that serves commercial subscribers and public safety personnel on 20 MHz of 700 MHz spectrum. It is found that NPV is greater for the public-private partnership than for the commercial-only network for any population density, which shows that the value of 10 MHz of spectrum exceeds the cost of meeting public safety requirements. Furthermore, the paper demonstrates that NPV/cell increases with population density, so urban areas are profitable and rural areas are unprofitable. The paper demonstrates that a partnership covering 94% of the US population breaks even because the most urban 56% of population subsidizes coverage for the next 38%. If initial deployment is subsidized, a financially sustainable public-private partnership can serve much more than 94%. Additionally, it is shown that allowing urban municipalities to opt-out of the partnership can significantly increase the subsidies required.     

基于ARM平台的无线网状网的构建

无线网状网作为一种新型的网络技术已经得到学术界和业界普遍关注和认可,也逐渐成为实现新一代互联网无线宽带接入层的基本网络技术。ARM平台作为通用式的嵌入式平台,其低功耗和高速的数据处理能力越来越受到无线通信领域的青睐。本文在论述了无线网状网的起源、定义、结构和特点的基础上,基于s3c2440的ARM平台设计了无线网状网的网络节点和路由器的硬件平台,并在ARM平台上实现了无线网状网协议,构建了无线网状网节点。     

基于GPRS数据传输智能终端的实现

介绍了利用单片机控制GPRS调制解调器模块实现GSM网络GPRS业务数据接入的智能终端系统,详细介绍了系统的硬件电路实现、单片机与GPRS模块的接口方式,以及嵌入式TCP/IP协议在本系统中的应用和实现。