Global System for Mobile Communications (GSM) is a digital cellular network that enables cellphones to connect with each other by searching for cells in the immediate vicinity. Being a fully digitized technology, GSM offers better speech quality to the cellphone users.
GSM is the second generation (2G) technology, which enables full duplex voice telephony. In a full duplex technology, a cellphone user can use one frequency for talking and another for listening. In simple words, both people on call can talk at once. The GSM technology, which started with full duplex voice telephony expanded over a period of time and started offering packet data transport via GPRS. Later on, the data transmission speed increased and EDGE was introduced. 3G is the new standard in the cellular technology, which offers better call & service support to users.
GSM is the largest mobile communication technology worldwide and the radio frequencies used for cellular networks are different in America, Asia, Europe, and Africa. A portion of radio frequency spectrum is allocated for cellphone usage and all mobile phone manufacturers develop products that support these assigned GSM frequencies.
What Provides GSM, Worldwide Acceptance?
The major advantage of GSM is its ubiquity. The technology supports multiple frequency levels i.e. 850MHz, 900MHz, 1800MHz, and 1900MHz.
• 850 MHz (U.S./Canada/Latin America/Brazil)
• 900 MHz (Africa/Europe/Brazil/Africa/Australia/Asia (ex Japan and S. Korea)
• 1800 MHz (Africa/Europe/Australia/Asia/Brazil)
• 1900 MHz (U.S./Canada/Latin America)
Since, GSM has acquired worldwide acceptance, it enables users to use single number with international roaming. So it is always better to use a cellphone supporting multiple frequency bands, because the device can seamlessly function if it supports at-least one of the network frequencies.
In simple words, if you have a GSM handset that supports multiple frequencies, you will not be required to change the number or handset, in case you are travelling to another country.
GSM Frequency Bands
There are different GSM frequency band combinations on which mobile phones operate.
Asian/European version – Dualband 900/1800 provides complete coverate in Asia, Africa, Europe, Australia, and Brazil but does not cover U.S./Canada/Latin America.
American version – Dualband 850/1900 provides complete coverage in U.S., Canada, Latin America, and Brazil but does not in Africa/Europe/Australia/Asia.
Asian/European version – Triband 900/1800/1900 gives complete coverage in Asia, Africa, Europe, and Australia & main cities in the U.S. and in some parts of Canada, Latin America, and Brazil.
American version – Triband 850/1800/1900 gives complete coverage in U.S., Canada, Latin America, Brazil and some parts of Africa, Europe, Australia, and Asia.
A quadband supports four frequencies – 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz. A GSM phone with quadband support can be used anywhere in the world.