HD: A Cache Storage Strategy Based on Hierarchical Division in Content-centric Networking

As a promising direction of future Internet, Content-Centric Network (CCN) has attracted world-wide attention. In-network caching is an important feature of CCN network, which has significant impacts on the performance of content transmission. Existing researches on in-network caching either have no regard for the collaboration or need giant additional overhead for global optimization. This paper proposes a hierarchical division-based cache storage strategy, called HD, which allows the contents can be cached in different nodes by grouping contents into different hierarchies. HD aims to reduce propagation delay and server load by light-weight collaboration mechanisms that allows the popular contents could be cached along the path with certain a probability. The performance of HD scheme was evaluated by comparing with the well-known schemes through simulation. The experimental results indicate that HD strategy can save up to 30.77% hop reduction ratio, 44.93% average cache hit ratio and 11.88% server hit ratio while the parameter α of Zipf distribution is increasing.