ABSTRACT
Wireless communications devices are ubiquitous components of the modern lifestyle in both industrialized countries and less developed areas of the world. Although mobile telephones and other wireless devices now seem essential for everyday life, their history of use is relatively short. In 1983, the Motorola DynaTAC 8000X was the first mobile phone approved by the Federal Communications Commission for use in the United States [1]. Growth in mobile phone usage since that time has been extraordinary: whereas the number of U.S. cell phone subscriptions in 1990 was equal to only 2% of the American population [2], the number of U.S. cell phone subscriptions in 2017 [3] approaches 75% of the American population.
