LRU-LC: Fast Estimating Cardinality of Flows over Sliding Windows

Estimating the cardinality of flows over sliding windows on high-speed links is still a challenging work under time and space constrains. To solve this problem, we present a novel data structure maintaining a summary of data and propose a constant-time update algorithm for fast evicting expired information. Moreover, a further memory-reducing schema is given at a cost of very little loss of accuracy. key words: streaming data, flow, sketch, cardinality, sliding window