From 1G to 5G

Wireless Mobile Communications have undergone major "generational" changes since MacDonald of Bell Telephone Laboratories introduced the concept of cellular communications in 1979. Over the last four decades, the technology has evolved from the first generation, 1 G, followed by 2 G, 3 G, and 4 G, to reach today's threshold of the fifth generation, 5 G. In order to grasp the magnitude of the impact 5 G is having on our society (5 G internet is expected cover up to 65% of the world's population by the end of 2025!), it is essential to understand the historical development of the previous generations. This review describes and explains the technology from 1 G to 4 G, culminating with the current state-of-the-art of 5 G, and its expected performance over the next ten years. We cover the major technical features of 5 G that differentiate them from the previous generations, in particular,the introduction of the MM-Wave spectrum combined with MIMO, Multiple Input-Multiple Output antenna arrays. We single out these two features as they provide orders of magnitude increases in channel capacity (20 Gb/s Downlink data transfer rates with reduced latency of 1 ms) and internet connectivity on the order of billions. We conclude with related 5 G marketing data, some of it related to the smart phone, a marvel of engineering and a credit to human creativity. 5 G is committed to connecting billions of devices with billions of people, both wirelessly and via the internet. Such a technical advance is a game-changer!