Mobile phone. Coloured X-ray of a mobile phone showing various components such as the circuit boards (red,lower frame),the earpiece (dark green at upper centre) and the antenna (at upper left). Mobile or cellular phones use low-power radio signals to transmit calls to a base station in the user's local area,or cell. A wide range of frequencies can be used in each cell because the signals are too weak to interfere with those in other cells. Base stations relay calls by cable to switching centres,from where calls can be transferred to other base stations,to the conventional telephone exchange,or to satellite stations for international calls | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Roberts, D. |
Bildgröße: | 2400 px × 2800 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |