GSM
Global System for Mobile Communications (GSM) is now the standard of mobile telephony, the most used in the world. The technology on the base of GSM is very different from those preceding it, above all because identification and conversation channels are digital. The biggest strong point of the GSM system has been the users’ possibility to enter new services at very low costs. For example the exchange of test messages (SMS) has been developed for the first time in GSM field. The frequencies used by the GSM network are 850, 900, 1800, 1900 MHz and change according to the layers where the same network is installed.
Usually the European Nations use the 900/1800 MHz frequencies, whereas the United States use the 850/1900 MHz frequencies. Thanks to the variety of the usable basics and the evolution of the transmission systems, the cells have multifrequency configurations (dual band).
DCS 1800 MHz
The DCS 1800 system is a GSM however it works on the range of 1800 MHz instead of 900 MHz. Recently better features of diffusion for the highest frequency have been developed and the cells are smaller, therefore it is particularly indicated for urban areas where the system creates more numerous connections compared to GSM 900.
UMTS
Universal Mobile Telecommunications System (UMTS) is the technology of mobile telephony of third generation (3G), successor of GSM. As far as the transmission interface is concerned, UMTS is compatible with the GSM. All UMTS cellular phones on the market till today (2004) are dual-mode UMTS/GSM type, they can send and receive calls through the already existing GSM. When a UMTS user enters an area not covered by the UMTS network, a UMTS terminal automatically commutes to GSM (with possible charge of the rates for roaming). If the user exits the area covered by UMTS during a telephone call, the call will be passed to the GSM network in a transparent way (i.e. the user does not realize it). On the contrary the GSM terminals cannot be used within UMTS networks.
UMTS does not work with the old GSM networks, it needs its own networks and antennas; Wind covers only big cities, Tre covers almost all the territory, TIM will do the same (however it has started later), whereas Vodafone is increasing its network in the rest of Europe, covering small towns. Considering that 70% of Italian people live in towns with less than 10000 inhabitants, most of the Country is excluded by the UMTS cover and it is possible that, without being informed, it purchases a cellular phone without any service. The Italian managers gather in a suitable database the covering requests with UMTS antenna: the committee for the project will decide to enter the locality in the list of those to cover. Note the important rule of the Local Administrations, whose legislation offers wide power of veto in the laying of new antennas, slowing down the covering plans foreseen by the managers.
Global System for Mobile Communications (GSM) is now the standard of mobile telephony, the most used in the world. The technology on the base of GSM is very different from those preceding it, above all because identification and conversation channels are digital. The biggest strong point of the GSM system has been the users’ possibility to enter new services at very low costs. For example the exchange of test messages (SMS) has been developed for the first time in GSM field. The frequencies used by the GSM network are 850, 900, 1800, 1900 MHz and change according to the layers where the same network is installed.
Usually the European Nations use the 900/1800 MHz frequencies, whereas the United States use the 850/1900 MHz frequencies. Thanks to the variety of the usable basics and the evolution of the transmission systems, the cells have multifrequency configurations (dual band).
DCS 1800 MHz
The DCS 1800 system is a GSM however it works on the range of 1800 MHz instead of 900 MHz. Recently better features of diffusion for the highest frequency have been developed and the cells are smaller, therefore it is particularly indicated for urban areas where the system creates more numerous connections compared to GSM 900.
UMTS
Universal Mobile Telecommunications System (UMTS) is the technology of mobile telephony of third generation (3G), successor of GSM. As far as the transmission interface is concerned, UMTS is compatible with the GSM. All UMTS cellular phones on the market till today (2004) are dual-mode UMTS/GSM type, they can send and receive calls through the already existing GSM. When a UMTS user enters an area not covered by the UMTS network, a UMTS terminal automatically commutes to GSM (with possible charge of the rates for roaming). If the user exits the area covered by UMTS during a telephone call, the call will be passed to the GSM network in a transparent way (i.e. the user does not realize it). On the contrary the GSM terminals cannot be used within UMTS networks.
UMTS does not work with the old GSM networks, it needs its own networks and antennas; Wind covers only big cities, Tre covers almost all the territory, TIM will do the same (however it has started later), whereas Vodafone is increasing its network in the rest of Europe, covering small towns. Considering that 70% of Italian people live in towns with less than 10000 inhabitants, most of the Country is excluded by the UMTS cover and it is possible that, without being informed, it purchases a cellular phone without any service. The Italian managers gather in a suitable database the covering requests with UMTS antenna: the committee for the project will decide to enter the locality in the list of those to cover. Note the important rule of the Local Administrations, whose legislation offers wide power of veto in the laying of new antennas, slowing down the covering plans foreseen by the managers.
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