Distributed delivery of popular videos over Ultra-dense networks

The application of video streaming is expected to shift to mobile broadband as soon as the Ultra-dense Networks (UDN) and High Efficiency WLAN (HEW) become popular. The motivation of this paper is to propose a distributed delivery scheme for streaming popular videos over UDN wireless environments. The H.264 SVC scalable source coding and the LT codes of rateless channel coding are both considered and integrated to provide reliable and scalable video services wirelessly. In the allocation phase, a hot video clip is both SVC encoded and LT encoded. Then, the coded data are randomly distributed among small-cell stations (SCs) or related attached servers. In the serving phase, one nearby SC immediately decodes its own LT coded data once a request issued and broadcasts them to the requesting user and the neighboring SCs to continue the undone decoding process in parallel. Thus, the clients can receive data from multiple SCs to achieve the goal of bandwidth aggregation. Besides, once the decoding process being completed, the repairing process is ignited to recover the possible node failure if exists. Two data allocation schemes are considered to balance the storage space, transmission bandwidth and fault tolerance requirements. In the ultra-dense scenarios, our simulations show that each request can be served with at least acceptable quality and with one more enhancement layer in average under communication loss rate less than 10% and possible node failures.