Telecommunication
The conventional telephone was invented independently by Alexander Bell and Elisha Gray in 1876. Antonio Meucci invented the first device that allowed the electrical transmission of voice over a line in 1849. However Meucci's device was of little practical value because it relied upon the electrophonic effect and thus required users to place the receiver in their mouth to "hear" what was being said. The first commercial telephone services were set-up in 1878 and 1879 on both sides of the Atlantic in the cities of New Haven and London.
Mobile phone industry in the United States
While it is "mobile phone" in British English, it is "cell phone" in American English. The term "cell phone", short for "cellular phone" came into the day-to-day American English vocabulary during the 1980s when the mobile phone companies had to distinguish their mobile phone that can be carried from one cell to another, each controlled by a land-based antenna, from the earlier Improved Mobile Telephone Service phones. In Wikipedia, "mobile phone" is more often used because it can be used across various technologies.