CHARMS: Cooperative hybrid architecture for relaying multicast satellite streams to sites without a satellite receiver

This paper describes an architecture dedicated to the terrestrial relaying of a real-time IP multicast audio-video stream broadcasted by a satellite. Such relaying is performed by nodes equipped with both a satellite receiver and a terrestrial Internet link. The stream is requested and obtained by sites that are not equipped with satellite receiving hardware but are nonetheless willing to receive it. By exploiting the properties of satellite transmission and adopting an hybrid satellite/terrestrial, multicast/unicast approach the described architecture allows to overcome the restrictions suffered by multicast traffic in the global Internet, allowing it to scale easily across autonomous systems.