Content, Topology and Cooperation in In-network Caching

M.Sc. Liang Wang will defend his doctoral thesis Content, Topology and Cooperation in In-network Caching on Friday the 27th of March 2015 at noon in the University of Helsinki Exactum Building, Auditorium CK112 (Gustaf Hällströmin katu 2b). His opponent is Professor Antonio Carzaniga (Università della Svizzera italiana, Switzerland) and custos Professor Jussi Kangasharju (University of Helsinki). The defense will be held in English.

Content, Topology and Cooperation in In-network Caching

In-network caching aims at improving content delivery and alleviating pressures on network bandwidth by leveraging universally networked caches. This thesis studies the design of cooperative in-network caching strategy from three perspectives: content, topology and cooperation, specifically focuses on the mechanisms of content delivery and cooperation policy and their impacts on the performance of cache networks.

The main contributions of this thesis are twofold. From measurement perspective, we show that the conventional metric hit rate is not sufficient in evaluating a caching strategy on non-trivial topologies, therefore we introduce footprint reduction and coupling factor, which contain richer information. We show cooperation policy is the key in balancing various tradeoffs in caching strategy design, and further investigate the performance impact from content per se via different chunking schemes.

From design perspective, we first show different caching heuristics and smart routing schemes can significantly improve the caching performance and facilitate content delivery. We then incorporate well-defined fairness metric into design and derive the unique optimal caching solution on the Pareto boundary with bargaining game framework.In addition, our study on the functional relationship between cooperation overhead and neighborhood size indicates collaboration should be constrained in a small neighborhood due to its cost growing exponentially on general network topologies.