**3. Timeline of Gs**

Communication technology progressed according to generations. The first generation analog communication started in the late 1970s and had a speed of 2.4 kpbs used for cellular telephones. Total access communication system (TACS), extended total access communication system (ETACS), and nordic mobile telephone (NMT) technologies were used in 1G. The main use was wireless phone call with high rate of phone drops and unclear voice.

The second generation used global system for mobile communication (GSM), general packet radio services (GPRS), and enhanced data rates for GSM evolution (*EDGE*) technologies with speed 56–64 kbps and 170 kbps when using EDGE. The second generation used digital technology rather than analog and the main uses were basic text, simple email, and snake game. The second generation included 2G, 2.5G, and 2.75G.

The third generation had four flavors: 3G, 3.5G, 3.75G, and 3.9G LTE. The speed reached 384 kbps and allowed Internet on the telephone and stream videos. 3G used universal mobile telecommunications system (*UMTS*) based on the GSM standard. While 3.5G used high speed downlink packet access (*HSDPA*) and high-speed uplink packet Access (*HSUPA*), followed by 3.75G which used high speed packet access (HSPA), an amalgamation of *HSDPA and HSUPA. 3.9G used* long-term evolution (LTE) standard.

The fourth generation 4G and 4.5G LTE reached 1 Gbps and 100 Mbps using multiple-input, multiple-output orthogonal frequency-division multiplexing (*MIMO*-*OFDM*). The result of such generation is HD steaming and video chats response with 0.04 ms with speed 300 MHz–3 GHz.

The fifth generation is promising millions of simultaneous connections, nearly 0 response time, massive MIMO, three times faster than 4G, and 0.001 ms response time. In short, 5G promises to be 1000 times faster than 4G. The applications of 5G are IoT, smart cities, games, autonomous cars, remote robots, drones, healthcare, and global positioning systems (GPS). Quantum cryptography for 5G security [14] is required to answer for breach of privacy in IoT. IoT, a term coined by Kevin Ashton rather than the well-known terms "embedded Internet" or "pervasive computing," will be more affected by 5G technology. Examples of objects that fall within the scope of IoT include connected security systems, thermostats, cars, electronic appliances (microwaves, fridges, washing machines, dryers, and coffee

makers), lights in household and commercial environments, alarm clocks, speaker systems, and vending machines. In the next sections, the chapter will discuss the three aspects of 5G: (1) Regulations, (2) security, and technology.
