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.

In this paper we present SRDP-Sign, a reliable multicast protocol designed to guarantee the reliable transmission of short messages via satellite as an extension of Satellite Reliable Distribution Protocol (SRDP). The uses of this protocol range from sending short text messages to transmitting information used for the improvement of networks' performances. The innovation of this protocol is that it has a high degree of scalability, reduced communication with receivers and fast delivery. In this paper we show the operations of the protocol, the underlying algorithms and analyse the protocol's behavior.

Security is an important concern in today's networking and particularly in satellite communication, where eavesdropping and active intrusion is much easier than in terrestrial fixed or mobile networks because of the broadcast nature of satellites. Many applications require the security feature of data confidentiality; in order to offer such capability, encryption keys must be constantly changed upon a membership change. If the keys are sent via multicast, that it is particularly useful for large groups, reliable multicast is required. In this paper we propose an efficient, reliable and multicast distribution of the encryption keys with SRDP-Sign (Satellite Reliable Distribution Protocol for Signaling). We guarantee reliability for all the receivers with a high degree of scalability. Total reliability error and the overall latency in the key distribution will be evaluated.

No abstract