--- title: "Evolution of mobile communication up to 3G" subject: "Wireless Communication" chapter: 1 key: "semester_7/wireless_communication:evolution-up-to-3g" source: https://www.bctengineer.com/q/semester_7/wireless_communication/evolution-up-to-3g site: BCT Engineering --- # Evolution of mobile communication up to 3G Wireless Communication · Chapter 1: Introduction - Asked in: 2074 Magh, 4 marks; 2072 Magh, 6 marks; 2071 Bhadra, 4 marks (asked 3 times) - Video: [Mobile Communication Generations](https://www.youtube.com/watch?v=bNbzcqFlLuU) — TutorialsPoint - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_7/wireless_communication/evolution-up-to-3g - Whole chapter: https://www.bctengineer.com/md/semester_7/wireless_communication/chapter-1 ## Question Briefly explain the development of mobile communication and the evolution path from 1G up to 3G technology. ## Short answer Cellular evolution began with analog 1G (AMPS/TACS), then digital 2G (GSM/IS-95) with SMS, 2.5G GPRS/EDGE added packet data, and 3G IMT-2000 (UMTS/CDMA2000) provided wideband CDMA up to 2 Mbps for mobile internet and video calls. ## Answer Mobile communication developed from early manual radio telephone systems to automatic cellular networks, and then through generations that added digital voice and finally mobile data. #### Early development (pre-cellular) - 1946: first public mobile telephone service in the USA (Mobile Telephone Service), single high-power transmitter, few channels, push-to-talk. - 1960s: IMTS (Improved Mobile Telephone Service) – automatic dialling, full duplex, but still very limited capacity. - 1970s: Bell Labs developed the **cellular concept** – small cells, low-power transmitters and **frequency reuse** – which solved the capacity problem. #### First generation (1G) – analog cellular (1980s) - Analog FM voice, FDMA, circuit switched. - Systems: AMPS (USA, 1983), NMT (Nordic), TACS (UK), NTT (Japan). - Problems: poor security (easy to eavesdrop), low capacity, no data, incompatible standards. #### Second generation (2G) – digital (1990s) - Digital modulation and speech coding, TDMA or CDMA, encryption, SMS. - Systems: **GSM** (Europe, TDMA, 200 kHz), **IS-136** (USA Digital AMPS), **IS-95** cdmaOne (CDMA, 1.25 MHz), PDC (Japan). #### 2.5G – data on 2G networks - **HSCSD** (circuit-switched multiple slots), **GPRS** (packet switched, up to ~171 kbps), **EDGE** (8-PSK, up to ~384 kbps), IS-95B. #### Third generation (3G) – IMT-2000 (2000s) - Wideband CDMA, 5 MHz carriers, up to 2 Mbps; video calls, internet, global roaming. - Systems: **UMTS/W-CDMA** (3GPP), **CDMA2000** (3GPP2), TD-SCDMA (China). Later HSPA (3.5G). ```text GSM → GPRS → EDGE ─┐ 1G → IS-136 ────────────┼→ W-CDMA/UMTS → HSPA (AMPS) PDC ───────────────┘ IS-95 → IS-95B ──────→ CDMA2000 1x → EV-DO 1G 2G 2.5G 3G ``` ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. Which idea developed by Bell Labs in the 1970s solved the capacity problem of early mobile telephone systems? A. A single high-power transmitter per city B. Push-to-talk operation C. Small cells with low-power transmitters and frequency reuse D. Analog FM modulation Answer: C. The cellular concept reuses frequencies in small low-power cells, greatly raising capacity. (Key point: Cellular concept) 2. Which was a problem of 1G analog systems? A. Poor security (easy eavesdropping), low capacity and incompatible standards B. Use of TDMA only C. Packet data speeds above 2 Mbps D. Mandatory SIM cards Answer: A. 1G was analog FM FDMA with little security and no common standard. (Key point: 1G problems) 3. Which 2.5G technology is packet switched and gives up to about 171 kbps on GSM? A. HSCSD B. EDGE C. GPRS D. TD-SCDMA Answer: C. GPRS is packet switched (~171 kbps); HSCSD is circuit switched and EDGE uses 8-PSK for ~384 kbps. (Key point: 2.5G upgrades) 4. Which pair are 3G IMT-2000 systems? A. GSM and IS-95 B. UMTS/W-CDMA and CDMA2000 C. AMPS and NMT D. GPRS and HSCSD Answer: B. 3G uses wideband CDMA with 5 MHz carriers: UMTS/W-CDMA, CDMA2000 and TD-SCDMA. (Key point: 3G systems) ## Related in Wireless Communication - [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× - [Evolution from 1G to 2.5G (TDMA)](https://www.bctengineer.com/question.md?key=semester_7%2Fwireless_communication%3Aevolution-1g-2g-2-5g-tdma) — Wireless Communication, chapter 1 - [Comparison of 1G to 4G mobile standards](https://www.bctengineer.com/question.md?key=semester_7%2Fwireless_communication%3Agenerations-1g-to-4g-comparison) — Wireless Communication, chapter 1, asked 6× - [Trends in wireless communication beyond 3G](https://www.bctengineer.com/question.md?key=semester_7%2Fwireless_communication%3Atrends-beyond-3g) — Wireless Communication, chapter 1 - [Short note: Interference in mobile communication](https://www.bctengineer.com/question.md?key=semester_7%2Fwireless_communication%3Ainterference-mobile-communication) — Wireless Communication, chapter 2 - [2G vs 3G, prioritized handoff, cell dragging](https://www.bctengineer.com/question.md?key=semester_7%2Fwireless_communication%3A2g-vs-3g-prioritized-handoff) — Wireless Communication, chapter 1 ## Related in other subjects - [Proposal for communication technology centre](https://www.bctengineer.com/question.md?key=semester_5%2Fcommunication_english%3Aproposal-communication-technology-centre) — Communication English, chapter 6 - [Appropriate technology and sustainable development elements](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Aappropriate-technology-sustainable-elements) — Energy Environment and Society, chapter 1 - [Impact of technology, sustainable development](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Atechnology-impact-society-sustainable) — Energy Environment and Society, chapter 1 - [Internet evolution and importance of web technology](https://www.bctengineer.com/question.md?key=semester_7%2Fweb_technology%3Ainternet-evolution-web-importance) — Web Technology, chapter 1