Global communication. Computer artwork representing global communications showing the Earth on the screen on a mobile telephone. Mobile or cellular telephones use low-power radio signals to transmit to a base station in the user's local area,or cell. A wide range of frequencies are used in each cell because the signals are too weak to interfere with those in other cells. Base stations relay calls to switching centres,from where calls can be transferred to satellite stations for international calls | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Victor Habbick Visions |
Taille de l’image : | 3694 px × 4291 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |