| Summary: | 碩士 === 國立成功大學 === 資訊工程學系 === 102 === With the increasing demands of multimedia streaming, Peer-to-Peer (P2P) technologies have been applied to live streaming systems due to low deployment cost and high scalability. However, P2P live streaming system still suffers a challenge when there are thousands of new peers want to join into the system in a short time, called flash crowd. When the system is under flash crowd, most of new peers suffer long startup delay. Related studies point out that peer over-competition during flash crowd is the main factor of making new peers suffer long startup delay.
Recent studies have proposed a slot-based user access control mechanism, which periodically determines a certain number of new peers to enter the system, and an user batch join mechanism, which divides new peers into several tree structures with fixed tree size. However, the slot-based user access control mechanism is difficult to accurately determine the optimal time slot length, and the user batch join mechanism is hard to determine the optimal tree size.
In this thesis, we proposed a structured access control (SAC) mechanism, which constructs new peers to a multi-layer mesh structure. The SAC mechanism constructs new peers’ connections in advance to replace periodical access control, and determines the number of peers in each layer by the system’s remaining upload bandwidth and the average video rate. Furthermore, based on heterogeneous upload bandwidth of peers, we propose an analytical model to represent the behavior of the system growth if the system can utilize the upload bandwidth efficiently. The analytical result has shown the same trend in system growth as the SAC mechanism. Additionally, the extensive simulations are conducted to show the SAC mechanism is better than two previously proposed methods in terms of system growth and startup delay.
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