Quality- and Context-aware Neighbor Selection for Layered Peer-to-Peer Streaming

Layered streaming is being considered as the most promising approach to adapt to bandwidth variations and heterogeneous end users in streaming applications. The goal of a layered streaming protocol is not only to optimize the average playback skip rate as in single-layer streaming, but also to maximize possible quality level (quality satisfaction) based on the available bandwidth capacity at the end user. In unstructured layered peer-to-peer streaming, however, achieving high quality satisfaction is challenging due to content and bandwidth bottlenecks. With experiments, in this paper, we demonstrate the importance and identify unique challenges of neighbor selection to the system performance in terms of the average skip rate and quality satisfaction. Then, we propose a new neighbor selection technique that can offer good performance while keeping the scalability of the mesh overlay under network fluctuations. The core of the technique is a preemption rule that allows a higher capacity peer to replace a lower capacity peer to be a neighbor of another peer with a certain probability. This preemption rule gears high capacity peers to good locations in the overlay to maximize the use of their bandwidth capacity and available layers. Simulation results demonstrate the efficiency of the method.