Introduction Wireless Communication Systems

I. Introduction

In the 1960’s voice communication was carried to end subscribers almost exclusively on copper wires running from central office switches to homes and businesses, and television was broadcast to homes almost exclusively through the air modulated on electromagnetic waves. By the late 1980’s, industry pundits began to observe that the situation was reversing itself. Increasingly, voice communication was carried to end subscribers through the air modulated on electromagnetic waves, while television was broadcast to homes on copper coaxial cables (soon to be followed by fiber optic cables). Now, as the 21st century approaches, the situation appears decidedly more complex. Cellular telephony continues to expand at a rapid rate; however, numerous plans exist for igh-speed wireless backbones carried across networks of earth-orbiting satellites, both geostationary and on-stationary, as well as networks of aircraft and balloons. In addition, several companies are devising plans to deploy broadband wireless distribution systems in order to compete with cable and copper twisted pairs for delivering high bandwidth data and television signals to businesses and homes. Further a variety of embedded and portable devices are beginning to appear, carrying built-in picocellular wireless communication transceivers. Two things appear clear. First, during the 21st century, wireless information technology will play a large role in the life of the country’s citizens and in the country’s economy. Second, the wireless technology landscape is so vast and complex that any organization seeking to enter the fray must take careful stock of the opportunities ahead. This white paper, on wireless information technology for the 21st century, aims to inform the trategic decision-making process within the Information Technology Laboratory (ITL) of the National Institute of Standards and Technology (NIST). The paper surveys the vast landscape of wireless information technology. In doing so, the paper attempts: (1) to identify market inhibitors facing various wireless technologies, (2) to make projections about the likely road ahead, and (3) to seek opportunities for the ITL particularly, and NIST more generally, to contribute to the removal of market inhibitors for key wireless technologies.

At the end, this white paper makes some recommendations on actions that the ITL and NIST should take to address the technological needs of the nascent wireless information technology industry. These needs include sharing the risk of development for key technical innovations and infrastructure standards, and providing the measurement science needed to inform industry decision-making when choosing among competing technical approaches to solve the difficult engineering problems inhibiting the successful deployment of wireless information technology.

II. Wireless Communications Systems

The market for wireless cellular telephony services has grown dramatically over the past 15 years, as wireless technology supporting such services has developed through two generations. At present, the wireless telephony industry is poised to develop and deploy a third generation of wireless systems that will increase spectral efficiency for voice users and offer flexible multimedia data services. The subsections that follow outline the progress of wireless telephony across all three generations, concentrating on the technical, economics, and standards battles raging with respect to the third-generation systems, which have yet to be deployed. The future of wireless communications

technology is considered in order to identify opportunities for NIST to help the industry realize its technical and economic promise. The section closes with a consideration of opportunities for NIST to influence the future course of wireless communications, which will surely be a growth industry in the 21st century.