---
title: "Comparison of 1G to 4G mobile standards"
subject: "Wireless Communication"
chapter: 1
key: "semester_7/wireless_communication:generations-1g-to-4g-comparison"
source: https://www.bctengineer.com/q/semester_7/wireless_communication/generations-1g-to-4g-comparison
site: BCT Engineering
---

# Comparison of 1G to 4G mobile standards

Wireless Communication · Chapter 1: Introduction

- Asked in: 2080 Bhadra, 4 marks; 2076 Bhadra, 6 marks; 2074 Bhadra, 6 marks; 2073 Magh, 4 marks (asked 4 times)
- Video: [Every Mobile Network Explained in 8 Minutes](https://www.youtube.com/watch?v=4BZg9YQy5WY) — Byte Sized Explainer
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/wireless_communication/generations-1g-to-4g-comparison
- Whole chapter: https://www.bctengineer.com/md/semester_7/wireless_communication/chapter-1

## Question

Compare and contrast the first, second, third and fourth generation of mobile communication standards in terms of technology advancement.

## Short answer

1G is analog FDMA voice; 2G digital TDMA/CDMA voice plus SMS and low-rate data; 3G wideband CDMA adds mobile data and multimedia; 4G uses OFDMA, MIMO and an all-IP packet core for broadband up to 1 Gbps. Key advances are digital modulation, packet switching, OFDM/MIMO and VoIP.

## Answer

Each generation of mobile communication brought a major change in technology: 1G was analog voice, 2G digital voice, 3G mobile data/multimedia, and 4G all-IP mobile broadband.

| Feature | 1G | 2G | 3G | 4G |
|---|---|---|---|---|
| Period | 1980s | 1990s | 2000s | 2010s |
| Signal | Analog | Digital | Digital | Digital |
| Main service | Voice only | Voice, SMS, low-rate data | Voice, video call, mobile internet | High-speed broadband, VoLTE, HD video |
| Standards | AMPS, NMT, TACS | GSM, IS-95 (cdmaOne), IS-136; GPRS/EDGE (2.5G) | UMTS (WCDMA), CDMA2000, TD-SCDMA; HSPA (3.5G) | LTE-Advanced, WiMAX 2 |
| Multiple access | FDMA | TDMA/FDMA, CDMA | Wideband CDMA | OFDMA (DL), SC-FDMA (UL) |
| Modulation | FM | GMSK, QPSK | QPSK, 16-QAM | QPSK to 64/256-QAM, MIMO |
| Channel BW | 25–30 kHz | 200 kHz (GSM), 1.25 MHz (IS-95) | 5 MHz | 1.4–20 MHz, aggregated to 100 MHz |
| Data rate | ~2.4 kbps | 9.6–14.4 kbps (EDGE ~384 kbps) | 384 kbps–2 Mbps (HSPA ~14–42 Mbps) | 100 Mbps mobile, 1 Gbps fixed |
| Switching | Circuit | Circuit (+packet in 2.5G) | Circuit + packet | All-IP packet |
| Security | None | Encryption (A5) | Better authentication | Strong (AES/SNOW) |

#### Key technology advancements
- **1G → 2G:** digital modulation, speech coding, error control, encryption, SIM card, better spectrum efficiency, SMS.
- **2G → 3G:** wideband CDMA with 5 MHz carriers, soft handoff, packet data, global roaming (IMT-2000), multimedia.
- **3G → 4G:** OFDM to combat multipath, MIMO antennas, flat all-IP architecture (eNodeB connects to the EPC), low latency (~10 ms), carrier aggregation; voice carried as VoIP (VoLTE).

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which sequence gives the multiple access techniques of 1G, 2G, 3G and 4G respectively?
   A. FDMA; TDMA/CDMA; wideband CDMA; OFDMA (DL) and SC-FDMA (UL)
   B. TDMA; FDMA; OFDMA; CDMA
   C. FDMA; wideband CDMA; TDMA; OFDMA
   D. CDMA; TDMA; FDMA; SC-FDMA
   Answer: A. 1G used FDMA, 2G digital TDMA/CDMA, 3G wideband CDMA and 4G OFDMA/SC-FDMA. (Key point: Multiple access per generation)

2. What is the switching technology of 4G compared with earlier generations?
   A. Circuit switching only
   B. Circuit plus packet, as in 3G
   C. All-IP packet switching, with voice as VoIP (VoLTE)
   D. Analog switching
   Answer: C. 4G is all-IP packet switched; voice is carried as VoIP (VoLTE). (Key point: Switching)

3. Which technology was introduced from 3G to 4G to combat multipath?
   A. Soft handoff
   B. OFDM
   C. FM modulation
   D. A5 encryption
   Answer: B. OFDM splits the channel into narrow subcarriers so each sees flat fading, handling multipath. (Key point: 3G to 4G advances)

4. Which set of features did 1G to 2G add?
   A. Digital modulation, speech coding, error control, encryption, SIM and SMS
   B. Video calls and mobile internet
   C. OFDM and MIMO
   D. All-IP core and VoLTE
   Answer: A. These are the 2G digital advances; video/internet is 3G and OFDM/MIMO/all-IP is 4G. (Key point: 2G over 1G)

## Close variants set in other exams

- [3G versus 4G mobile communication](https://www.bctengineer.com/question.md?key=semester_7%2Fwireless_communication%3A3g-vs-4g) — Wireless Communication, chapter 1, asked 6×

## Related in Wireless Communication

- [Evolution of mobile communication up to 3G](https://www.bctengineer.com/question.md?key=semester_7%2Fwireless_communication%3Aevolution-up-to-3g) — Wireless Communication, chapter 1, asked 3×
- [Benefits of wireless communication and 4G](https://www.bctengineer.com/question.md?key=semester_7%2Fwireless_communication%3Awireless-benefits-4g) — Wireless Communication, chapter 1

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