The first generation(1G) mobile wireless communication network was discovered in the 1980s. It depends on analog signals used for voice calls only. In 1990, the 1G was replaced by the second generation (2G) which uses digital signals network.

The 2G, also known as the Global System for Mobile Communications (GSM), provided text messages besides voice calls with low data rates. The third generation (3G) was then launched in 2001 to support multimedia transmission with higher data rates, speed and capacity. The Long-Term Evolution (LTE) which refers to the fourth generation (4G) was established in 2009. The 4G provides broadband internet services and applies new technology called Orthogonal Frequency Division Multiplexes (OFDM) which is one of Multi Input Multi Output (MIMO). Wireless mobile internet was supported in 4G and the Quality of Service (QoS) was increased by increasing the bandwidth and reducing the cost of resources [1].

The fifth generation (5G) followed the 4G in 2019 with mobile services extending the services m humans to things in industries. Researchers are still exploring the sixth generation (6G) to meet the world’s requirements and needs of higher rates and higher speeds [2].

First Generation 1G

1G stands for the first generation of mobile wireless mobile communication system networks. It is an analog technology designed to provide basic voice-calling services in the 1980s. 1G network was based on the Frequency Division Multiple Access technology (FDMA) technology with the following properties:

•         Frequency band = 824-894 MHz
•         Channel capacity = 30 KHz
•         Speed = 2.4 kbps.
•         The bandwidth was extended later (in 1988) to be almost 10MHz and called Expanded Spectrum.

Second Generation 2G

 2G refers to the second generation of wireless mobile communication systems, offering voice calls, text messaging, and limited mobile internet using digital signals. The two main digital modulation schemes used in 2G are Time Division Multiple Access (TDMA) and Code Division Multiple Access (CDMA). TDMA divides transmitted signals into different time slots, while CDMA assigns each user a unique code for communication over a multiplex physical channel. As 2G networks were primarily designed for voice transmission, their speed was limited to 64kbps, with a bandwidth ranging from 30-200KHz.

Third Generation 3G

The introduction of the third generation wireless mobile communication system took place in 2000, aiming to provide enhanced data rates in both wide coverage areas (ranging from 144kbps to 384kbps) and local coverage areas (up to 2Mbps). Compared to its predecessors, 3G offers users advanced services, including data services, access to TV/videos, web browsing, e-mail, video conferencing, paging, fax, and navigational maps. It operates within a bandwidth of 15-20MHz, facilitating high-speed internet, video chatting, and other multimedia applications.

Fourth Generation 4G

The fourth generation of mobile systems, known as 4G, emerged in the late 2000s as an all-IP based network system. The primary objective of 4G technology was to provide high-speed, high-quality, high-capacity, secure, and cost-effective voice and data services, multimedia, and internet over IP. With capabilities ranging from 100Mbps to 1Gbps, 4G networks required multimode user terminals capable of selecting the appropriate wireless system. Terminal mobility played a crucial role in 4G, enabling automatic roaming between different wireless networks and ensuring wireless services anytime and anywhere.

 Fifth Generation 5G

The fifth generation (5G) of mobile and wireless communication networks represents a revolutionary advancement towards a fully interconnected wireless world, supported by key technologies like LAS-CDMA, OFDM, MC-CDMA, UWB, Network-LMDS, and IPv6. Positioned as the perfect real wireless world, 5G transcends limitations, offering unlimited access to information and data sharing capabilities for the global benefit.

At its core, 5G boasts data speeds that average around 150 to 200 Mbps, effectively supporting real-time applications, such as self-driving cars, manufacturing processes, virtual reality (VR), and various Internet of Things (IoT) services. Leveraging Orthogonal Frequency Division Multiple Access (OFDMA), the 5G New Radio (NR) technology ensures efficient spectrum utilization and low latency rates of less than one millisecond, particularly relevant for real-time services.

In addition to its data capabilities, 5G networks include Voice over New Radio (VoNR) or Voice over 5G (Vo5G), akin to IP-based voice calling (VoLTE) in LTE networks. This functionality underscores the network's commitment to seamless voice communication alongside its data-driven capabilities.

Sixth Generation 6G

The sixth generation (6G) of mobile and wireless communication networks envisions a seamless integration of satellite communication networks and 5G technology, providing unparalleled global coverage. These satellite networks encompass telecommunication, earth imaging, and navigation satellites, with the overarching goal of 6G being to interconnect these systems to offer network position identification, multimedia, internet connectivity, and weather information services to mobile users. While the integration of 6G with 5G and satellite networks presents immense potential, it poses significant challenges concerning handoff and roaming due to the existence of four different standards. Nevertheless, advancements in radio-over-fiber systems and the emergence of 6G technology promise to bring mankind closer to any potential extraterrestrial civilization in the universe, representing a remarkable leap in connectivity.

Noteworthy features of 6G include ultra-fast internet access with data rates reaching up to 10-11 Gbps, enabling the realization of smart homes, cities, and villages [4].

References:

1. Anju,G. (2015). An Overview on Evolution of Mobile Wireless Communication Networks: 1G-6G. International Journal of Communication Technology,
2. Jiang, W.; Han, B.; Habibi, M.A. (2021) Schotten, H.D. The road towards 6G: A comprehensive survey. IEEE Open J. Commun. Soc.  2, 334–366
3. Hong, W.; Jiang, Z.H.; Yu, C.; Hou, D.; Wang, H.; Guo, C.; Hu, Y.; Kuai, L.; Yu, Y.; Jiang, Z.; et al. (2021). The Role of Millimeter-Wave Technologies in 5G/6G Wireless Communications. IEEE J. Microwaves
4. Shahen Shah, A.F. (2022) ‘A survey from 1g to 5G including the advent of 6G: Architectures, multiple access techniques, and emerging technologies’, 2022 IEEE 12th Annual Computing and Communication Workshop and Conference (CCWC) [Preprint]. doi:10.1109/ccwc54503.2022.9720781.