A solution for a transparent GSM retransmission system into confined areas

Radio cellular systems depend upon the widespread availability of two-way communications between vehicles and control centers. Radio propagation inside tunnels and urban radioelectric shadowed areas is disturbed with strong attenuation, multipath, waveguide and masking effects. Special care must be taken to avoid communication failure in road transport informatics (RTI) applications based on the radio frequency system in those specific areas. To achieve the extension of the RTI road-vehicle digital communication systems to the coverage of confined areas, specific electronic and electromagnetic problems must be solved. Elements are given to realize a pan-European GSM (Global System for Mobile communications) radiating retransmission system in those confined areas.