Main Intuition:Average Case Consider the following scheme: Popularity Only perform coded caching among most "popular"files 1 to N1 0 The average transmission rate for the "popular"files will be upper- bounded by the worst-case rate: K'--N M。 1 Ni File 1+ M Index N whenever K'>>N1/M 。 If these files are indeed very popular,K'will be large.Thus,the expected rate will likely be close to this upper bound Ni-1 M →Once a file is“oopular'”,its popularity does not matter! 11• Consider the following scheme: – Only perform coded caching among most “popular” files 1 to N1 • The average transmission rate for the “popular” files will be upper￾bounded by the worst-case rate: whenever K’ >> N1 /M • If these files are indeed very popular, K’ will be large. Thus, the expected rate will likely be close to this upper bound Once a file is “popular”, its popularity does not matter! 11 Main Intuition: Average Case File Index Popularity 𝑁1 1 1 1 1 1 1 ' (1 ) (1 ) 1 ' 1 M N M N K N M N M K M N • − •  − = − + ? 1 1 N M −