Wireless phones which receive their signals from towers. A cell is typically the area (several miles) around a tower in which a signal can be received. Cell phones provide array of functions. Depending on the type of mobile phone we can store contact information, keep track of appointments and set reminders, Use the built-in calculator for simple math, send or receive e-mail, get information (news, entertainment, stock quotes) from the internet, play games, watch TV, send text messages, integrate other devices such as PDAs, MP3 players and GPS receivers. A cell phone is a full-duplex device meaning that both people on the call can talk at once. Division of a city into small cells allows extensive frequency reuse across a city, so that millions of people can use cell phones simultaneously. Cell phones operate within cells, and they can switch cells as they move around. Cells give cell phones incredible range. Someone using a cell phone can drive hundreds of miles and maintain a conversation the entire time because of the cellular approach. Each cell has a base station that consists of a tower and a small building containing the radio equipment. The cell phones have evolved from Analog to Digital which has been described in the previous chapter. This chapter describes the two main standards for mobile phones i.e. GSM and WAP.
TopIntroduction
A mobile phone also known as a cellular phone, cell phone and a hand phone is a device that can make and receive telephone calls over a radio link while moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile phone operator, allowing access to the public telephone network. In addition to telephony, modern mobile phones also support a wide variety of other services such as text messaging, MMS, email, Internet access, short-range wireless communications, business applications, gaming, photography and many more commercial applications. Mobile phones that offer these and more general computing capabilities are referred to as Smartphone. The first hand-held mobile phone was demonstrated by Dr. Martin Cooper of Motorola in 1973, using a handset weighing around 1 kg. In 1983, the DynaTAC 8000x was the first to be commercially available. In the twenty years from 1990 to 2011, worldwide mobile phone subscriptions grew from 12.4 million to over 5.6 billion, penetrating the developing economies and reaching the bottom of the economic pyramid. The first mobile telephone call made from a car occurred in St. Louis, Missouri and USA on June 17, 1946, using the Bell System's Mobile Telephone Service. In 1956, the world’s first partly automatic car phone system, Mobile System A (MTA), was launched in Sweden. MTA phones were composed of vacuum tubes and relays, and had a weight of 40 kg. Martin Cooper, a Motorola researcher and executive is considered to be the inventor of the first practical mobile phone for handheld use in a non-vehicle setting, after a long race against Bell Labs for the first portable mobile phone. Using a modern somewhat heavy portable handset, Cooper made the first call on a handheld mobile phone on April 3, 1973.
There has been a remarkable evolution in the functioning and working mobile phones. Depending on the requirements of the users and the services provided by different service providers. The two standards for mobile devices are:
- 1.
GSM based Handsets.
- 2.
WAP based Handsets.
TopArchitecture Of Gsm Handsets
The GSM infrastructure is composed of Mobile station, a Base station Sub System, Network Station and Operation and support System. Each component plays an important role in data exchange process.(Huynh, 2003; Nguyen, 2003).
Mobile Station
Mobile Station is the technical name of the mobile or the cellular phone. The mobile station (MS) comprises all user equipment and software needed for communication with a mobile network.
The mobile station refers to global system connected to the mobile network, i.e. mobile phone or mobile computer connected using a mobile broadband adapter. This is the terminology of 2G systems like GSM. In the 3G systems, mobile station (MS) is now referred as user equipment (UE). The mobile station consists of two main elements:
Mobile Equipment
It is also called as mobile device. There are different types of devices distinguished principally by their power and application. With the highest evolution of GSM the weight and volume of this equipment are continuously decreasing. The life of a battery between charging is also decreasing. The evolution of technologies allowed decrease of power to0.8 W. Mobile equipment has a unique number called as mobile equipment identifier(MEID) identifying a physical piece of mobile station equipment.