CoNAT: A Network Coding-based Interest Aggregation in Content Centric Networks

Interest aggregation is one effective technique used in content-centric networking to speed up content delivery and reduce load on the network and the content sources. Interests, i.e. requests, for one content chunk are grouped together so that only the first Interest is forwarded toward the content source, and consequently, only one reply, i.e. Data, is responded for the whole Interest group. Ordinary Interest aggregation, however, is limited to Interests for the same content chunk which means Interests for a content should closely synchronize in time to be able to aggregate. In this paper, using network coding, we remove such limitation: An Interest for an encoded chunk of a content can be aggregated with a previous Interest for virtually any other encoded chunk of that content which contains new information. The crucial point is how to quickly verify the novelty of information contained in an encoded chunk. Our proposed network coding-based Interest aggregation is lightweight and effectively increases the number of Interests which can be aggregated. As a result, it reduces content delivery time as well as the load on network and content sources compared with the ordinary Interest aggregation without network coding. Simulation results confirm the effectiveness of our proposed method.