Let us begin by learning about GSM.
GSM is a standard set produced by European Telecommunications Standards Institute (ETSI) to represents technologies for second-generation (2G) digital mobile system. The GSM standard is more enhanced after the development of the third-generation (3G) UMTS standard created by the 3GPP.
GSM phones can be recognized by the existence of a Subscriber Identity Module (SIM). This is a very small object, which is about as broad as a finger, is a removable smart card that includes a user’s subscription data, and some contact entries.
This SIM card enables a user to switch from one GSM phone to another. In some countries, especially those in Asia, GSM phones are secured to a definite carrier. However, if a user handles unlocking a phone, it can add any SIM from some carrier into the same phone.
The main disadvantage of GSM is that several users share the equivalent bandwidth. This can generate interference and because of interference bandwidth limitation appears.
The second disadvantage of GSM is that it can generate electronic interference. That is the reason why sensitive areas like hospitals and airplanes need a cell phone to be turned off otherwise it can generate interference with the apparatus of hospitals and airplanes.
UMTS represents the Universal Mobile Telecommunications System. UMTS is a third-generation mobile cellular technology for networks that depends on the GSM standard. It is produced by the 3GPP (3rd Generation Partnership Project). UMTS is a component of the International Telecommunication Union IMT-2000 standard set and analyze with the CDMA2000 standard set for networks based on the CDMA technology.
UMTS works Wideband Code Division Multiple Access (W-CDMA) radio access technology to supports larger spectral efficiency and bandwidth to mobile network work.
UMTS determines a complete network system, covering the radio access network (UMTS Terrestrial Radio Access Network, or UTRAN), the substance network (Mobile Application Part, or MAP), and the authentication of clients via SIM cards. The technology defined in UMTS is also defined as Freedom of Mobile Multimedia Access (FOMA) or 3GSM.
The nature of UMTS will be the ability to provide multi-component calls and multiple simultaneous calls. As an example, a user can be involved in a video conference that uses both a speech and a video element and simultaneously initiates an interactive computer session from a personal computer linked to the UMTS terminal.
The element of UMTS is expected to be the support for multiple operating environments (public, domestic, and business) using an individual terminal. Global roaming among these environments will also be applicable.