Information-Centric Communication in Mobile and Wireless Networks

Information-centric networking (ICN) is a new networking paradigm to cope with drawbacks of host-based communication, namely scalability, flexibility and security. In ICN, routing is based on named data instead of endpoint identifiers, thus, content can be cached in any nodes and requests and be routed towards the closest content source. In my thesis, I am investigating several aspects of ICN in the context of wireless and mobile networks. First, we explore different content discovery algorithms to explore available content names. Content discovery is necessary before content retrieval takes place because sometimes preferred content may not be available. In this case, requesters may also be satisfied with second-best options. Then, we investigate several mechanisms to increase efficiency of information-centric wireless communication. This includes adaptive retransmission timers in case of collisions, Raptor coding to increase diversity of broadcast data transmissions, and multi-hop routing protocols, which route requests towards areas where content sources have been found. Since every request includes a content name, it is possible to aggregate similar requests from different users such that only a fraction of the requests need to be forwarded to the content source. We investigate routing approaches for both connected and disrupted (delay-tolerant) networks. Furthermore, cache sizes in ICN are limited because they require fast memory to support line-speed operation. We explore a hierarchical caching approach, where real-time data is stored in fast (volatile) caches while popular delay-tolerant content is additionally stored on persistent storage. Although memory access times are slightly slower on persistent storage, persistent caching may still result in faster content retrieval times when applied to edge nodes because requests do not need to be further forwarded.