Satellite - Digital Multimedia Broadcast (S-DMB) is a satellite based overlay network for a terrestrial UMTS network. S-DMB is intended to deliver multimedia content to mobile handsets. The system can deliver real-time streaming TV-programs and multimedia services as well as non real-time push and store multimedia services to mobile users.
The system concept is based on a high power geostationary satellite and a network of medium and low power terrestrial repeaters. These repeaters function as gap-fillers to provide urban indoor coverage. The repeaters can be co-located with mobile base stations. The signals of the satellite and the terrestrial repeaters are synchronized so that the mobile handset can combine the incoming signals to improve the reception.
The S-DMB system uses the satellite band (2170-2200 MHz) of IMT-2000. S-DMB can deliver around 18 channels at 128 kbps in 15 MHz. The system has been designed to be fully compliant with the UMTS Multimedia Broadcast/Multicast Service (MBMS). This makes integration of S-DMB in an UMTS terminal fairly easy.