Content-access QoS in peer-to-peer networks using a fast MDS erasure code

This paper describes an enhancement of content access Quality of Service in peer to peer (P2P) networks. The main idea is to use an erasure code to distribute the information over the peers. This distribution increases the users’ choice on disseminated encoded data and therefore statistically enhances the overall throughput of the transfer. A performance evaluation based on an original model using the results of a measurement campaign of sequential and parallel downloads in a real P2P network over Internet is presented. Based on a bandwidth distribution, statistical content-access QoS are guaranteed in function of both the content replication level in the network and the file dissemination strategies. A simple application in the context of media streaming is proposed. Finally, the constraints on the erasure code related to the proposed system are analysed and a new fast MDS erasure code is proposed, implemented and evaluated

MITV, a solution for interactive TV based on IP multicast over satellite

Television is the most popular audiovisual application ever used. The technological headways in digital transmissions allow new interactive services to complement classical Television broadcasts. However, the solutions available need specific infrastructures often making them hard and costly to deploy. MITv is a proposition for interactive television to be deployed using association of current distribution television systems (e.g., satellite DVB-S, cable DVB-T, TV over xDSL, etc.) and classical Internet infrastructure. MITv makes use of the natural association between broadcasted TV programs and associated interactive contents to manage replication of those contents over an ad-hoc infrastructure. The replication phase can be based on IP Multicast over satellite service, providing a high performance and realistic way to convey the interactive content over the geographically distributed replication units. The proximity between replication units and end-users then allow a very high quality for interactive media presentation by the way of an access network such as xDSL. The MITv system was entirely developed and tested in real conditions through a satellite/xDSL network emulator