Mobile cellular telephony is one of the greatest innovations of the 20th century and today in the 21st century, it can be safely said that it has brought nothing less than a revolution in the way communications take place across the globe.
Mobile cellular telephony is enabled through a combination of cellular networks and mobile devices which communicate with each other by means of the radio frequency spectrum (i.e., wirelessly). A cellular network consists of thousands of nodes that assist mobile device users in performing a plethora of tasks. Mobile devices have become the third screen after television and computer and are becoming more economical and powerful with continual technological advancements. There are more than 5 billion mobile subscribers in the world and for the vast majority, mobile devices have become a necessity. Without them, they cannot go about their daily routine lives.