Mobile communication systems all over the world use a wide range of frequencies. They use decimeter waves, the length of which is from 10 cm to 1 m. This range includes waves with a frequency of 300 MHz to 3 GHz.
The same frequency band is also used by television, Wi-Fi and Bluetooth. Among the frequency ranges, there are those that have been allocated specifically for mobile phones.
Historically, the radio waves used for mobile communications systems in America, Europe, Africa and Asia differ from each other.
Technology standards and frequencies
The first technology standard used for commercial use in the United States was AMPS with the 800 MHz band. In the countries of northern Europe, the NMT-450 technology was first introduced, the range of which was 450 MHz.
Along with the growing popularity of mobile phones, manufacturers faced a problem: they could not provide a service to a large number of people. They had to develop existing systems and introduce a new standard with a different frequency range.
In Japan and some European countries, the TACS standard with the 900 MHz band has appeared. The GSM standard, which replaced the NMT-450 technology, also used the 900 MHz band. As the demand and market for cell phones grew, providers purchased licenses to use the 1800 MHz band.
Lower frequencies allow providers to cover larger areas, while higher frequencies enable service providers to reach more customers in a smaller area.
Modern technology standards
The current generation of mobile devices operates mainly on the GSM standard. The UMTS standard is also gaining popularity. In some countries, technologies of the ELT, 3G, 4G formats are used.
Each standard or format uses a frequency range of two frequencies. The low frequency band transmits information from the mobile device to the station, and the high frequency band transfers information from the station to the mobile one.
Many GPS phones cover three frequency bands: 900, 1800, 1900 MHz or 850, 1800, 1900 MHz. These are the so-called tri-band phones or tri-band devices. With such a phone, it is convenient to travel the world, and it does not require replacement when
moving to another country.
Mobile networks of different formats can use the same frequencies. This is, for example, the 800 MHz band used in at least four different formats.
The amount of frequencies available for use by mobile devices is limited. This should be taken into account when the number of users increases. This means that the base station can provide a limited number of people, and the communication network needs to be constantly expanded.
Cell phones of the main providers in Russia operate at 900 MHz and 1800 MHz. At the same time, Megafon, Beeline, MTS use both bands, and TELE 2 only uses the 1800 MHz band.
