Mobile TV is considered by many to be the next “killer application” for the handset market, and many standards—DVB-H, MediaFLO, T-DMB, or ISDB, for example—are already available for deploying this service. The market expansion of mobile TV, however, is not meeting original expectations, in part due to high infrastructure costs and the availability (or lack thereof) of frequencies.
A new standard, Digital Video Broadcasting – Satellite Services to Handheld Devices (DVB-SH), has been proposed for accelerating the deployment of mobile TV in the next few years.
DVB-SH is a hybrid satellite and terrestrial system derived from the DVB-H and ETSI satellite digital radio standards. The DVB-SH system has been designed for frequencies below 3 GHz, typically the UHF, L, and S-band. It complements the existing DVB-H physical layer standard, and like DVB-H, uses the DVB IP Datacast (IPDC) set for content delivery, electronic service guide, and service purchase and protection standards. A channel bandwidth of 1.7 MHz has been added to the DVB-H standard’s original four allowed channelizations: 5, 6, 7, and 8 MHz.
A DVB-SH system is generally used to deliver content and data to handheld terminals via satellite, but whenever a line of sight between terminal and satellite does not exist, terrestrial repeaters provide the missing coverage. More precisely, low and medium power repeaters in urban areas offer indoor coverage and more capacity.