DVB-S2 in Railway Environments: An Exploratory Study for Tunnel Coverage

In this paper we address the problem of DVB-S2 signal reliability in railway tunnel environments. We have focused our attention on the selection of the most suitable frequency band to be used in the tunnel coverage by gap fillers and on its impact on in-tunnel propagation and handover between satellite and gap fillers. The propagation characteristics, i.e. attenuation, of several bands in and out of the tunnel are provided adopting an EM (waveguide) approach. A handover procedure between satellite Ka/Ku band and selected ISM band for gap fillers is also proposed