In a mathematical sense, the curvature is the reciprocal of the radius, so that a smaller curvature implies a large radius. A curve of large radius, as for a railway, cannot be laid out by using the radius directly. We will see how the problem of laying out a curve of large radius is solved.
In 1983, Motorola released its first commercial mobile phone, known as the Motorola DynaTAC 8000X. The handset offered 30 minutes of talk-time, six hours standby, and could store 30 phone numbers. It also cost Â£2639 ($3995). In the very early days of the mobile space handsets werenât designed with consumers in mind.
Dr. Martin Cooper. Engineer, and Inventor of the Mobile Phone. Martin Cooper-Inventor Of The Cellphone. Dr Martin Cooper, a former general manager for the systems division at Motorola, is considered the inventor of the first portable handset and the first person to make a call on a portable cell phone in April 1973. The first call he made was to his rival, Joel Engel, Bell Labs head of research.