Performance of Caching-Based D2D Video Distribution with Measured Popularity Distributions
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On-demand video accounts for the majority of wireless data traffic. Video distribution schemes based on caching combined with device-to-device (D2D) communications promise order-of-magnitude greater spectral efficiency for video delivery, but hinge on the principle of "concentrated demand distributions." This letter presents, for the first time, evaluations of the spectral efficiency of such schemes based on measured cellular demand distributions. In particular, we use a database with more than 100 million requests (689,461 for cellular users) from the BBC iPlayer, a popular video streaming service in the U.K., to evaluate the throughput-outage tradeoff of a random caching D2D based scheme, and find that also for this realistic case, order-of-magnitude improvements can be achieved. The gains depend on the size of the local cache in the devices; e.g., with a cache size of 32 GB, a throughput increase of two orders of magnitude at an outage probability between 0.01 and 0.1 can be obtained.
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