The second iteration of mobile wireless technology. It represents a significant advancement over the earlier 1G systems (such as AMPS and NMT) and introduced digital communication to the mobile industry. 2G networks emerged in the late 1980s and early 1990s, replacing analog systems with more efficient and versatile digital technology.
The key features and improvements introduced by 2G technology include:
- Digital Voice Transmission: 2G networks used digital modulation techniques, such as Time Division Multiple Access (TDMA) or Code Division Multiple Access (CDMA), to convert voice signals into digital data. This resulted in better call quality, improved capacity, and reduced interference.
- Data Services: 2G introduced data services alongside voice calls. Initially, these services were relatively slow, allowing for basic data transmission like Short Message Service (SMS) and low-speed data connectivity.
- Encryption and Security: Compared to 1G systems, 2G provided improved security features, such as encryption algorithms, to protect voice calls and data transmission from unauthorized access.
- International Roaming: With 2G, mobile network operators could establish agreements for international roaming, enabling users to access services outside their home network coverage area and even in different countries.
2G networks were further divided into two primary standards:
- Global System for Mobile Communications (GSM) is the most widely used 2G standard globally. It employs TDMA technology and offers better interoperability among different operators and countries. GSM became the foundation for subsequent generations of mobile technology.
- Code Division Multiple Access 2000 (CDMA2000) is an alternative 2G standard based on CDMA technology. It provides increased capacity and enhanced voice and data services. CDMA2000 was primarily used in North America and some parts of Asia.
2G technology revolutionized the mobile industry by providing improved voice quality, data services, and international connectivity. It paved the way for the rapid development of subsequent generations of mobile technology, including 3G, 4G, and now 5G networks.