GSM (Global System for Mobile Communications): This is the primary 2G technology standard.
CDMA (Code Division Multiple Access): Another 2G technology standard, primarily used in North America and parts of Asia.
Technical Features:
Data Transmission: 2G provided digital voice services and introduced data services like SMS (Short Message Service) and MMS (Multimedia Messaging Service). Data speeds typically ranged from 9.6 kbps to 64 kbps.
Frequency Bands: 2G operates in the 900 MHz and 1800 MHz frequency bands (for GSM) and 800 MHz (for CDMA).
Voice Encoding: Used various codecs like Enhanced Full Rate (EFR) and Adaptive Multi-Rate (AMR) for voice compression to optimize bandwidth usage.
Security: Introduced encryption methods to secure voice and data transmission, though it was not as secure as later generations.
Limitations:
Data Speed: Limited data speeds restricted the capabilities of 2G for multimedia content and high-speed internet browsing.
Capacity: Lower capacity compared to later generations, leading to congestion in high-density areas.
Advanced Services: Limited support for advanced services like video calling and high-quality streaming.
3G (Third Generation)
3G Technologies:
UMTS (Universal Mobile Telecommunications System): A popular 3G technology.
CDMA2000: Another 3G standard, mainly used in North America and parts of Asia.
HSPA (High-Speed Packet Access): An upgrade to UMTS offering higher data rates.
Technical Features:
Data Transmission: 3G introduced high-speed data transmission, allowing users to access the internet, stream videos, and make video calls. Data speeds typically ranged from 384 kbps to several Mbps (depending on the variant).
Frequency Bands: Operates in various frequency bands, including 850 MHz, 1900 MHz, and 2100 MHz.
Voice and Data Integration: Enhanced voice quality and simultaneous voice and data transmission capabilities.
Security: Improved security with better encryption algorithms and protocols compared to 2G.
Advanced Services: Support for advanced services like video calling, mobile TV, and high-quality multimedia streaming.
Limitations:
Deployment Cost: Higher infrastructure and deployment costs compared to 2G.
Battery Life: 3G devices typically consumed more power than 2G devices due to higher data transmission rates.
Summary:
2G focused primarily on voice communication with limited data capabilities, operating in specific frequency bands.
3G represented a significant advancement with high-speed data transmission, improved voice quality, and support for advanced services, operating in various frequency bands.