Hier-DHT: Structured P2P-based hierarchy search model for time-shifted streaming

In the current, the structured P2P-based time-shifted streaming system exist the problems that the copy of time-shifted streaming cannot be fully found and the maintenance costs are higher. For resolving the problems a structured P2P-based hierarchy search model for time-shifted streaming, namely Hier-DHT, is proposed. In Hier-DHT, the hierarchy is divided according to the first video block in the cache of node. The nodes that cache the same first video block form a layer. Nodes are divided into layer node and layer-in node. All layer nodes form a ring. Layer node is brought by election of nodes in the layer. All register information is registered in layer node. Routing a lookup request is only on the ring formed by layer node. By the design, the video block cached can be fully found and the maintenance costs can be decreased effectively. Experimental results show that compared with other model, Hier-DHT has a better cache hit ratio, the better lookup performance and the lower maintenance overhead.