User:HIEU.N

Modern mobile phone systems are cellstructured. Radio is used to communicate between a handset and a cellsite. Communication between cellsites and the public switched telephone network can be by digital microwave radio, digital optic fiber or digital copper land lines communicating with a telephone exchange. A computer is a device or machine for making calculations or controlling operations that are expressible in numerical or logical terms. Computers are made from components that perform simple welldefined functions. The complex interactions of these components endow computers with the ability to process information. If correctly configured usually by programming a computer can be made to represent some aspect of a problem or part of a system. If a computer configured in this way is given appropriate input data, then it can automatically solve the problem or predict the behavior of the system.