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.
The mobile or cell phone was invented by Martin Cooper in 1973. The history of the cell phone shows that Nathan Stubblefield had a patent in 1908. However the patent was for cave radio phones and not the mobile device as we know it today.Early History.As stated, Stubblefieldâs patent was for cave radio telephones, as the device was known then.irst Generation Phones. Cooperâs invention was patented on October 17, 1973. the first phone call was made by Cooper months before he applied for the patent, on April 3, 1973. He made the call to Dr. Joel Engel, a researcher at AT&Tâs Bell Labs.