ABSTRACT
The modern smartphone suddenly, within the span of a few years, became a must-have device for most people. The smartphone represents the convergence of many modern technologies in one lightweight handset. Mobile phones became cellular phones when coverage areas were divided into cells. Each cellular area has its own directional antennas on a transmission tower or tall structure. Android and iOS are the two dominant mobile operating systems for smartphones and tablets. Smartphones are wonderful. One convenient handset can combine a touch-screen tablet, mobile phone, still/video cameras, and additional devices such as microphone, speaker, flash light, global positioning system, and other sensors. Some health issues can arise as a result of excessive use of smartphones. The Unstructured Supplementary Service Data (USSD) is a protocol allowing cell customers to access/set account information and features by dialing short codes right from their phone.
