OpenSatRelaying: a Hybrid Approach to Real-Time Audio-Video Distribution over the Internet

Abstract

In spite of massive research efforts devoted to the advance of the technologies for large-scale live distribution of audio-video IP streams, no totally satisfying solutions seem to have emerged so far. CDNs are still expensive and P2P-TV systems face substantial delay limitations. As the deployment of a global terrestrial IP multicast infrastructure still looks far, turning the attention to satellite-based multicast would seem a sensible choice. However, the cost of such technology has been a stumbling block until now. That is where the CHARMS architecture comes in. It is designed to take advantage of the formidable properties of the satellite without requiring a generic user to install any sort of satellite receiver or dish. Its cornerstone is the recursive terrestrial relaying of satellite streams a number of properly equipped hosts are able to receive. The present paper relates about the results of the OpenSatRelaying project, aimed at the implementation and testing of the CHARMS architecture.

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“…To overcome such limitations, the CHARMS (Cooperative Hybrid Architecture for Relaying Multimedia Satellite Streams) architecture [36] was developed on top of the ALRM (Application Layer Relaying Module) library [37]. There are two kinds of nodes in a CHARMS overlay (figure 1): relayers (R i ), equipped with the proper antenna for satellite reception, and hosts (H i ), connected only to the terrestrial Internet (typically through a domestic ADSL network).…”