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. |