четверг, 31 марта 2011 г.

Invention of the mobile phone

Hello, dear students! Let's answer the question: How have the mobile phones changed since invention?
Respectfully Яна Олеговна.


1 комментарий:

  1. The earliest mobile telephones were dubbed first generation telephones, often referred to as 1-G. These devices were the very first real mobile telephones, although they were then known as cellular mobile radiophones, and were based on analogue signalling. Second generation (2G) mobile phones were first released in the nineties. Unlike 1-G phones that were analogue, 2G phones use digital signalling to provide voice services and for text messaging & WAP internet access. The name 2.5G is used to refer to the phone technology that is post 2G, but not quite 3G.