this will help you to understand the technology used in your phones and development from their initial stage. how was the initial look of devices. how it will connect with base station and let you help in better communication, internet connectivity.

1. Mobile Telephone
System
Designed by:
Vishweshwar Manaw
B.Sc. IT (III Sem)

2. Classification of Mobile Phones Systems
• First Generation Mobile Phones
(Analog Voice)
• Second Generation Mobile Phones
(Digital Voice)
• Third Generation Mobile Phones
(Digital Voice and Data)

3. • In 1946, the first system for car-based telephones was
set up in St. Louis.
• Also known as Push-to-
Talk Systems were
installed in Taxis, Police
cars, CB-radio.
• This system had only
single channel.

4. • In 1964, MTS were replaced by IMTS (Improved Mobile
Telephone System).
• It had two frequencies instead of one i.e., two channels
were used, one for sending
and one for receiving.
• IMTS supported about
23 channels ranging from
150 MHz to 450 MHz.

5. • This system was invented
by Bell labs and first
installed in the United
States in 1982.

7. The Base Station
consists of a
computer and
transmitter/receiver
connected to an
antenna. They are
just like radio relays.

8. It refers to the process of transferring an active call or data
session from one cell in a cellular network to another or
from one channel in a cell to another.
Soft Handoff
In this handoff, the cell phone is acquired by the new
base station before the previous one signs off.
Hard Handoff
In it the old base station drops the cell
phone before the new one acquires it.

9. • The AMPS system uses 832 full-duplex channels, each
consisting of a pair of simplex channels.
• Each cell phone in AMPS has a 32-bit serial number and
a 10-digit mobile number in its PROM.
• The mobile number is represented as a 3-digit area code
in 10 bits, and a 7-digit subscriber number in 24 bits.
• Away from all its features AMPS focused only on voice
i.e., its supported only voice transmission.

10. Second Generation
Mobile Phones
• This system is termed as the digital system where the
voice is transmitted digitally.
• Second Generation is categorised into main three systems:
D-AMPS, GSM, CDMA.
• The beginning of the second generation started by the
formation of ETSI (European Telecommunications Standards
Institute) in 1988.
• There was a starting of Data Service.

11. • It is the modified form of AMPS and it was also used
along with the AMPS.

12. • GSM is also called as Global System for Mobile.

13. Structure of GSM

15. • It is also known as Code Division Multiple Access.
• It is sometimes also called as IS-95 (International
Standards-95) as it is described in IS-95.
• The brand name cdmaOne is also used.
• Instead of dividing the frequency CDMA uses to
transmit the entire frequency all the time.
• CDMA uses coding theory for multiple simultaneous
transmissions.

16. • The Third generation can provide both digital data
and voice communication.
• The Third generation concept started in 1992.
• It support for packet-switched and circuit-switched
data services.
• It provides high-quality voice transmission and data
rate >5 Mbps and supports Multimedia.