A novel two tiered proxy caching scheme for video on demand applications

Considering the constant increase of network traffic, and existing bandwidth limitations, caching Internet objects is an essential technique to improve the provided quality of service and to reduce the network load. Caching is particularly helpful for video objects due to their interactive nature, large size, long playback duration, real time constraints, and typically variable bit rate. Several caching schemes for video streams have been proposed in the literature. The performance of the existing methods generally degrades in applications like video on demand where random access is common. In this paper a new two tiered proxy caching scheme for random access applications has been proposed. The proposed design consists of two layers: the cache layer and the fetch layer. The cache layer divides the incoming video stream into small segments, and selects the segments that should be cached based on their current access probability and the utility they provide. The fetch layer organizes the outgoing requests according to the priority it assigns to them. Simulation results indicate that the proposed technique outperforms existing caching schemes when random access is significant. The provided utility is up to three times better than the existing solutions.