Question: Which of the following is the world’s first cellular system to specify digital modulation and network level architecture?
A GSM
B AMPS
C CDMA
D IS-54
Answer: GSM
| Technology |
Full Name |
Description |
| GSM |
Global System for Mobile Communications |
· GSM was the world’s first cellular system to specify digital modulation and level architectures and services.
· It was developed to solve the fragmentation problems of the first cellular systems in Europe.
· It uses TDMA (Time Division Multiple Access) to divide a frequency band into time slots.
· It operates in various frequency bands around the world and is widely used for 2G (second-generation) mobile communication.
· GSM offers voice and data services and supports features like text messaging (SMS) and caller ID.
· It is known for its international compatibility and strong encryption. |
| AMPS |
Advanced Mobile Phone System |
· AMPS was an analog cellular technology widely used in North America during the 1980s and 1990s.
· It used Frequency Division Multiple Access (FDMA) to divide the frequency band into channels.
· AMPS was primarily designed for voice communication and had limited capacity for data services.
· It has been largely replaced by digital technologies like GSM and CDMA. |
| CDMA |
Code Division Multiple Access |
· CDMA is a digital cellular technology that uses spread spectrum techniques to allow multiple users to share the same frequency band simultaneously.
· It provides excellent call quality, increased capacity, and improved security compared to analog technologies.
· CDMA is used in 2G and 3G networks and is known for its efficient use of spectrum. |
| IS-54 |
Interim Standard 54 |
· IS-54, also known as AMPS-DC (AMPS Digital Cellular).
· It was an early attempt to introduce digital capabilities into the existing AMPS analog cellular network.
· It used FDMA to create digital channels within the AMPS framework. IS-54 allowed for some digital features like text messaging and improved call quality.
· It had limitations in terms of data services and capacity compared to later digital technologies like CDMA and GSM. |
