The SkyScraper™ system delivers rich, digital media content to large numbers of receivers, obviating the need for expensive, high-bandwidth Internet connections. This enables sustainable applications such as... Dynamic Digital Signage Frequently updated, high-impact, multimedia material and associated indexes and playlists can be distributed easily to large numbers of in-store video screens, tourist kiosks, billboards, and other types of digital signs. Homeland Security Disaster alerts and other emergency relief information may be distributed quickly and reliably to local police and fire stations, hospitals and other first responders. Receiver targeting and encryption can protect sensitive information, limiting access to authorized recipients. Education and Training All educational materials, including live lectures, can be delivered conveniently and economically to schools, training centers, and even home computers, giving both students and teachers top quality support for both self-paced and interactive learning. Video/DVD on Demand Satellite and terrestrial broadcasters can offer access on-demand to videos, music, DVDs, etc., on a subscription or pay-per-view basis, using a cost efficient push-and-store model of delivery to disks on set-top boxes. Software Download Service Broadcasters and cable operators can offer consumer electronics manufacturers software download service for updating their DTV receiver software, based on the ATSC, DVB, or SCTE software download specifications.