Adaptive Multi-source Streaming in Heterogeneous P2P Networks
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This paper presents a novel approach for adaptive multi-source streaming in peer-to-peer (P2P) networks, addressing the challenges of bandwidth variability and sender heterogeneity. The proposed Peer-to-Peer Adaptive Layered Streaming (PALS) mechanism leverages a receiver-driven architecture, dynamically adjusting the target quality based on real-time bandwidth measurements. The system employs a sliding window technique to optimize packet requests from various sources, enhancing the quality while minimizing packet loss. Performance evaluations demonstrate that PALS effectively manages bandwidth fluctuations and improves streaming quality.
Adaptive Multi-source Streaming in Heterogeneous P2P Networks
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Presentation Transcript
Adaptive Multi-source Streaming in Heterogeneous Peer-to-peer Network Vikash Agarwa; Reza Rejaie Twelfth Annual Multimedia Computing and Networking (MMCN ’05)
Agenda • Introduction • Assumptions and Target Environment • PAL • Sliding Window • Quality Adaptation • Packet Assignment • Performance Evaluation • Conclusion
Introduction • P2P streaming requires • Overlay construction • Content Delivery • Challenges • The available bandwidth from each sender is not known a priori and could significantly change during a session • Different senders have different bandwidth and RTT, or even leave
Introduction • Multi-source MDC : Commonly used separate layer for each sender Drawback: • Available bandwidth may be too small • Available bandwidth may be too large • Unpredictable variation needs complicates inter-layer synchronization
Introduction • Propose P2P Adaptive Layered Streaming (PALS) • Receiver driven • Heterogeneous senders • Periodically determine the target quality (i.e. the number of layers) that can be streamed • Relatively low amount of receiver buffering • Can be used in non-interactive streaming application
Assumptions & Target Environment • Request a single video from group of senders • UDP connections and TCP-friendly congestion control • Sender differs from bandwidth and RTT and bottlenecks • Assume provided information of senders (PRO) • Assume layered coded • Assume all layers have same constant bit rate, C.
PAL Mechanism • Receiver monitors EWMA bandwidth from each senders • Sliding Window (SW) • Tewma = Tjewma • Predict total number of incoming packet : K = (Tewma*∆)/pktsze • Quality Adaptation (QA) • Number of active layer that can be played • Packet from each layer to be request in future
PAL Mechanism • Packet Assignment (PA) • Divides selected packets into disjoint subnet • Sends a separate request to each sender • Each sender maintains a single list of pending packets for each receiver peer
Sliding Window Δ : buffering window = 5*SRTT δ : minimum threshold. If exceeds -> slide window
Sliding Window • Drawback : • Duplicate request -> low • Overestimating bandwidth -> overwriting request, packet ordering • Underestimating bandwidth -> idle, further request (window overlap)
Quality Adaptation • Invoke once per window • If (Tewma >= n * C) , utilize the excess bandwidth to request future packet • BUFadd : Total buffer data before adding a layer • If (Tewma < n * C), drain the buffer~~, drop top layer
Packet Assignment • Weighted round-robin • Partially Available content : two pass • Treat all senders have the entire content • Per-packet assignment
Performance Evaluation Window overlap = 20% Nc = 5 C = 80KBytes/sec δ=2*SRTTmax
Quality comparing single and multiple layer static streaming
Duplicate packet • Low duplicate packets – 8% • Duplicates decrease as window size increase • Loss remains below 5%
Conclusion • Multiple-source MDC streaming • Sliding Window uses for predicting number of incoming packets • Quality Adaptation uses for balance between the quality and the potential loss • Packet Assignment deals with the packet distribution among the senders