MOBILE

Mobile is a movable device made by martin copper. Mobile can be divided into two parts hardware and software. Therefore, hardware consist of electronics and mobile parts. Electronics consist of current, voltage, resister, capacitor, diode, coil, transformer and transistor. Mobile is a comunicating device, it is wireless communication.

INTRODUCTION OF MOBILE PHONE
Philips lasis dicovered the principle of telephone in1816. Alexander Grahm bell invented the telephone in 1876. Galieno marconi demonstrated wireless telography in 1895. Jhon baird transmitted TV signal across atlantic in 1920. Martin copper is the father of mobile phone.
GENERATION OF MOBILE
Mobile is generated into four generation.
FIRST GENERATION

• It is heavy and compatible in size.
• They were half duplex.
• Valve were used.
• There is no more features only talking.
• It is out of date.
  SECOND GENERATION
• It is lighter than first generation
• It consist of many features mainly SMS(short measaging service).
• Both alphabatic and numeric were used.
• It consist of small B/W(black & white) picture and smileys.
• It ws full duplex.
• It consist of monophonic ringtone
  
  THIRD GENERATION
• It consist of more feature than second generation.
• It had MMS feature(Multimedia messaging service).
• It had colour picture video clip, vidieo chating etc.
• It had poly phonic ringtone as well as internet facility such as WAP(wireless application protol), GPS(general packet radio service), EDGE( Enhanced data rate for Global evolution).
• It had one more faciclities i.e. data transmission.
  
  FOURTH GENERATION
• It will be 3 to 5 times faster than Third generation.
• It is expected that it will be launched till 2010.
  CELL PHONE
  CELL PHONE is the phone which is connected with the radio signals without any wire. cell phone is developed from cellular technology. cellular technology can be divided into two parts i.e. GSM(global system of mobile communication) & CDMA ( code division multiple acess).
  GSM(Global system of mobile communication)
• It is used for first time technology.
• SIM card is used in this technology.
• IME number is used.
• Mobile number is free from the set.
• It consist of many bands such as 850/900/1800/1900 MHz.
• In nepal for NTC 900MHz & for Mero 900/1800 MHz
  CDMA(Code division multiple Acess)
• No SIM card is used n this technology.
• ESN(Electronic serial number) is used.
• Mobile number is included with the set.
• In Nepal UTL(United telecom limited) and Sky are providing CDMA.
  ADVANTAGES
• It has high network power.
• It cost low and gives high performance.
• It has long life battery.
• If the set is stolen or missed, It can be found easily
  In some CDMA, extrnal is used which looks like SIM that is called R-UIM (Removable user interface module)