Definitely Mobile phone is an excellent communicating device. But it is not a new invention but the improvisation of the crude wireless device invented by Perry Long in 1940.The first fully Automatic mobile phone system, called MTA (Mobile Telephone system A), was developed by Ericsson and commercially released in Sweden in 1956.
In April 1973, Dr Martin Cooper, former general manager for the systems division at Motorola, invented the mobile phone prototype and he made the first call to Joel Engel, his research rival, head of research at Bell Labs. This is the first Mobile phone call.
Mobile phone is primarily designed for Voice communication. In addition to the standard voice function, new generation mobile phones support many additional services, and accessories, such as SMS ( Short Messaging Service) for text messaging, email, packet switching for access to the Internet, gaming, Bluetooth, camera with video recorder and MMS ( Multi Media Messaging Service) for sending and receiving images, video ,songs etc.
The mobile phone system is referred to as cellular telephone system because the coverage area is divided into “cells “each of which has a base station antenna.The mobile phone tower can communicate to 8 mobile phones in 1 second through time sharing method. The signals are in the form of packets to give two way transmission.
The secret of the mobile phone is its SIM (Subscriber Identification Module).The SIM is a form of digital Smart Card containing the user’s subscription information and a phone book. SIM Securely stores the service subscriber key having 15 digits. First 3 digits indicates Mobile country code, Second 2 digits indicate Mobile network code and the Third 10 digits indicates the Mobile station identification number ( Local station that is connecting).
When you first activates the SIM card, every details like, mobile phone make, pin number, area code, area of activation, server code etc will be recorded automatically in the SIM as well as in the server data base. So it is easy to trace the mobile communication and location if there is a complaint regarding misuse. Let us see what is happening when we use the Cell phone...