MEMS Reconfigurable Radios: System Development and Entry Costs in Wireless Phones

无线电频谱促进了各种各样的应用和服务，但已经变得过于拥挤，特别是在过去二十年中。随着通信技术的发展，越来越多的业务依赖于高数据速率频谱接入。这些关键服务包括银行、社会保障、远程医疗和技术信息交换。随着新应用的出现和现有应用的不断增长，对频谱资源的需求越来越大。不幸的是，为一个新的无线运营商获得全国范围的宽带接入是昂贵的，部分原因是每个地区只有有限数量的频谱许可证。这个项目研究了一组创新，使全国范围的进入成本更低。美国无线电话服务行业由四家大型全国性提供商主导。根据美国联邦通信委员会的无线竞争报告，无线行业的市场份额集中到一定程度，可能会引发其他行业的反垄断调查。鼓励新的全国性竞争者进入这个行业符合公众利益。新进入者面临的一个主要障碍是在全国范围内获得无线牌照，即在每个地区获得一个或多个牌照。使用目前的技术，组装这样一个覆盖全国的区域的成本相当高，因为目前的无线电需要移动设备在每个地区使用类似的一套频谱频段进行操作。如果未来的无线电技术允许进入者在全国范围内从许多不同的频段集合，每个地区一个或多个频段，那么获得所需许可证的成本可能会降低。进入成本的降低可能会鼓励新的国家供应商进入市场，增加竞争，降低消费者的成本。因此，未来的无线电需要支持广泛的频率范围，以便能够在不同的地区选择不同的频段。这就需要多标准可重构无线电。这种无线电还可以通过调谐到在任何给定时间使用最少的频率和标准来缓解与有限的频谱可用性和有限的开放带宽相关的问题。本研究的目的是开发可重构无线电的最必要组件，并评估这种无线电为无线业务中的新竞争者降低频谱获取进入成本的能力。现有的多标准无线电解决方案最多支持5个标准，并基于多个滤波器之间的切换来选择不同的频段。此方法不可扩展。此外，现有的无线电不能重新配置以选择新开放的频段，例如VHF/UHF电视频段。本研究通过以下方法解决上述问题：1)开发小型化微机械可调谐滤波器以及硬接触大功率微机械发射/接收开关，以最大限度地降低整个系统的复杂性和成本；2)实现新的柔性无线发送和接收集成电路方案，通过利用CMOS缩放和增强收发器的灵活性来降低成本。3)基于所提出的可重构无线电技术，在市场进入成本的背景下进行实证估计和解释。这项研究将对国民经济产生变革性的影响。它使全国范围内的宽带以更低的成本接入无线电频谱，并增加了无线服务提供商之间的竞争。竞争的增加可以通过与四家现有的全国性公司竞争的新公司的进入而发生。消费者福利会随着价格的降低和竞争的增加而增加。

The radio spectrum facilitates a wide variety of applications and services but has become overly crowded, especially in the past two decades. With advances in communications, more and more services rely on high data rate spectrum access. These critical services include banking, social security, telemedicine, and the exchange of technical information. Spectrum resources are in ever-greater demand as new applications emerge and existing ones continue to grow. Unfortunately, acquiring nation-wide broadband access for a new wireless carrier is costly in part because there are only a limited number of spectrum licenses per territory. This project investigates one set of innovations to make national-scale entry less costly. The US wireless phone service industry is dominated by four large, national providers. According to the FCC's Wireless Competition Report, market shares in the wireless industry are concentrated to a degree that would provoke antitrust investigation in other industries. It is in the public interest to encourage the entry of new, nationwide competitors into this industry. A major hurdle for a new entrant is assembling a nationwide footprint of wireless licenses, i.e. one or more licenses in each territory. The cost of assembling such a nationwide coverage area is quite high using current technologies as current radios require mobile devices to operate using a similar set of spectrum bands in each territory. If future radio technologies allow an entrant to assemble a nationwide footprint from many different frequency bands, one or more for each territory, the cost of acquiring the needed licenses may be lower. This lowering of entry costs may encourage new national providers to enter the market, increase competition, and lower costs to consumers. Future radios are thus required to support a wide range of frequencies to be able to select different bands in different territories. That calls for multi-standard reconfigurable radios. Such radios can also mitigate the problems associated with limited spectrum availability and limited open bandwidth by tuning to the frequency and standard that is least heavily used at any given time. It is the purpose of this research to develop the most necessary components of a reconfigurable radio and to evaluate the ability of such radios to reduce spectrum acquisition entry costs for new competitors in wireless service.Existing solutions for multi-standard radios support a maximum of five standards and work based on switching between a number of filters for selecting different bands. This method is not scalable. Also, existing radios cannot be reconfigured to select newly opened bands, such as VHF/UHF TV bands. This research addresses the above mentioned issues by 1) developing miniaturized micromachined tunable filters as well as hard-contact high-power micromachined transmit/receive switches to minimize the overall system complexity and cost, 2) implementing new flexible wireless transmitter and receiver integrated circuit schemes to reduce the cost by leveraging CMOS scaling and enhancing the flexibility of the transceiver, and 3) producing empirical estimates and interpreting them in the context of market entry costs based on the proposed reconfigurable radio technology. This research will have transformative impacts on the national economy. It enables nationwide broadband access to the radio spectrum at lower costs and increases competition between wireless service providers. An increase in competition can occur through the entry of new firms that compete with the four incumbent, national firms. Consumer welfare will be higher with lower prices and the higher consumption from increased competition.