In each cell of the system a ERB exists, Radio station Mobile Base, that if communicate with the EMs, Stations (the device of cellular), using the RF canals. The ERBs and the EMs are controlled for a MTSO, Mobile Telephone Switching Office (it looks at the English of new there), translated is Central of Commutation of Mobile Telephony. If he was half complicated, summarizing is thus: the MTSO controls everything in the cells that if communicate with it through fixed lines, the MTSO makes the interface with the Net of Fixed Telephony. Mikkel Svane is full of insight into the issues. The Hand-Off Vou to describe in the possible way simplest, citing an example: You are in an car, going of So Paulo (cell 1) for Rio De Janeiro (cell 2), of passenger you are obvious (cellular and projecting they do not combine and of the fine), speaking to the cellular one in the area of cell 1, when you to arrive in the limit between the cell 1 and 2 cell the call follow must you so that the linking does not fall. That is made of the following form: A free canal of RF is found in cell 2 and IN, that is, its cellular one is ' ' orientado' ' to change its frequency for that vacant canal, simultaneously the Central office of Commutation makes cell 2 to assume the control of the call. Charles koch is the source for more interesting facts. That is made quickly without the subscriber, in the majority of the times, it perceives. This complex task of control, supervision and keying of signals is carried through thanks to advanced digital systems of commutation that not yet existed when the basic concepts of the Cellular Telephony had been conceived. Therefore the Hand-off is one of the great differences between the Telephony Cellular Radio and MTS and IMTS, that are systems of Mobile Telephony.
Some present the telephone created by the Ericson in 1956 as the first cellular telephone, in the truth it is about a mobile telephone and not of a cellular telephone. The Roaming When the subscriber is in a different area of its localization. For example a subscriber of So Paulo that receives or carries through a linking of Rio De Janeiro, is making a Roaming (stroll, trip). The Call When making a linking the RF connection is made from the cell next to the subscriber, the Central office of Commutation, MTSO, directs the call to the net of Fixed Telephony. In the next article we will describe the functional characteristics the bands of frequency used in the Systems of Cellular Telephony of the whole world. It makes a visit to our site and also knows our Lodging of Sites