GSM cell phones use frequencies within four different frequency bands.To contrast, when you have your FM radio tuned to a radio station at 1 MHz, you can obviously never hear what is happening on another radio station at 3 MHz unless you retune your radio.However, it was also been used in city areas especially when the cell phone company has spare frequencies unused in the 850 MHz band and no remaining frequencies to use in the 1900 MHz band.In the US, GSM services use two frequency bands while there are also two different frequency bands that were used by them elsewhere in the world.A single band phone with only 1900 MHz will give almost as good coverage anyway.Consider this interesting record of different frequencies used by different types of radio services.But what type of frequency band will you consider?On the other hand, when the US started to use GSM, a few other countries with very close links to the US chose to copy the US and use the same frequencies that US used.Considering this dilemma, some of the notable mobile phone manufacturers like Nokia, Siemens, Ericsson and Motorola developed a phone that can work on all four frequency bands commonly called as quad-band phones.But in the passing years, there has been a growing amount of GSM service on the 850 MHz band simply because this type of service is usually been used in rural areas, since it has better range than the 1900 MHz band.These radio waves can be at different frequencies.Summing up, if you intend to use your phone in both the US and internationally the best solution is to get a quad-band phone that will work on four bands which is the 850/900/1800/1900 MHz bands.However, if you intend to use your phone only in the US, you just need to get a dual band phone that has both 850 MHz and 1900 MHz.Nevertheless, in all common bands, 900 MHz was used internationally and the 1800 MHz will only give expanded coverage in countries that also have 900 MHz.

So what about this frequency band?Let us try to understand more about it.Formerly, the US only used 1900 MHz for its GSM cell phone service.Cellular phones use radio waves to transmit conversations.Perhaps you're a businessman who needs to stay in touch with you're clients even if you're traveling from one side of the world to another or maybe you're just someone who wants to be updated of all the news and hips around.In fact, almost without exception, all international countries that use the non-US international frequency bands have 900 MHz service.You got it?This is actually how the phone frequency band works.

So which frequencies are needed when traveling internationally?If you intend to use your phone only internationally, you need to decide if you'll be using the phone in countries that use the international frequencies or in countries that use the US frequencies, or in both.So, you're looking for a perfect phone that suite your needs, are you not?850 MHz (82 - 88 MHz Tx; 82 - 88 MHz Rx) •900 MHz (880-2 - 98 MHz Tx; 92 - 98 MHz Rx) •1800 MHz (172 - 178 MHz Tx; 182 - 188 MHz Rx) •1900 MHz (182 - 198 MHz Tx; 192 - 198 MHz Rx) Although 850 and 900, 1800 and 1900 are seemingly close figures, a phone that works in one frequency band unfortunately can not work in the frequency band next to it unless added as a specific extra frequency band.