Different generations of mobile telephone systems A stage or stage of increasing use and development of mobile phones is called mobile phone generation. The mobile technology invented so far can be divided into four generations. Below is a detailed discussion about its generation. First generation: In 1983, the first generation of mobile phones commercially introduced in North America, called AMPS (Advanced) Mobile Phone System) used AMPS analog signals to communicate. Its link channels are separated by FDMA (Frequency Division Multiple Access) method. This system uses two analog channels, namely — forward and reverse, base station reverse. Besides, there were two other mobile phone systems in operation called first generation CT/1 and NMT. First generation mobile systems have the following features -- (i) This generation uses analog system of radio signals. (ii) Cell signal encoding method is FDMA. (iii) Mobile phones are smaller in size and lighter in weight than the typical telepho...