Even among major metropolitan areas, however, the cost of wireless service can vary by 10 percent or more. This covers programming and the cost of a new phone. The majority of cellular phone services offer some type of plan- such as a monthly fee for call minutes, also referred to as airtime. Unlike regular phone services, wireless phones charge for outgoing and incoming calls. Charges are higher for peak-period use which are daytime weekdays and less for evenings, weekdays, and holidays.
Some carriers offer a certain amount of free minutes on off-peak days.
The telephone was invented by Alexander Graham Bell in 1876, and wireless communication can trace its roots to the invention of the radio in 1894 by a young Italian named Guglielmo Marconi. In the dark ages before cell phones, people who really needed mobile communications ability installed radio telephones in their cars. In the radio telephone system, there was one central antenna tower per city, and perhaps 25 channels available on that tower. The genius of the cellular system is the division of a city into small cells. This allows extensive frequency reuse across a city, so that millions of people can use cell phones simultaneously.