Ubaid Abbasi

An efficient playout smoothing mechanism for layered streaming in P2P networks

Layered video streaming in peer-to-peer (P2P) networks has drawn great interest, since it can not only accommodate large numbers of users, but also handle peer heterogeneity. However, there’s still a lack of comprehensive studies on chunk scheduling for the smooth playout of layered streams in P2P networks. In these situations, a playout smoothing mechanism can be used to ensure the uniform delivery of the layered stream. This can be achieved by reducing the quality changes that the stream undergoes when adapting to changing network conditions. This paper complements previous efforts in throughput maximization and delay minimization for P2P streaming by considering the consequences of playout smoothing on the scheduling mechanisms for stream layer acquisition. The two main problems to be considered when designing a playout smoothing mechanism for P2P streaming are the fluctuation in available bandwidth between peers and the unreliability of user-contributed resources—particularly peer churn. Since the consideration of these two factors in the selection and scheduling of stream layers is crucial to maintain smooth stream playout, the main objective of our smoothing mechanism becomes the determination of how many layers to request from which peers, and in which order. In this work, we propose a playout smoothing mechanism for layered P2P streaming. The proposed mechanism relies on a novel scheduling algorithm that enables each peer to select appropriate stream layers, along with appropriate peers to provide them. In addition to playout smoothing, the presented mechanism also makes efficient use of network resources and provides high system throughput. An evaluation of the performance of the mechanism demonstrates that the proposed mechanism provides a significant improvement in the received video quality in terms of lowering the number of layer changes and useless chunks while improving bandwidth utilization.

Delivering scalable video coding using P2P Small-World based push-pull mechanism

Peer-to-Peer (P2P) networks have proven to enable large-scale content distribution over the Internet thanks to peers organization in overlays. However, real-time content delivery such as live and video on demand (VoD) streaming applications requires significant consideration in term of peer organization to provide concurrent users with adequately satisfying viewing experiences. In this paper, we present an adaptive video streaming mechanism that constructs overlay networks based on Small-World (SW) of peers. Our approach combines the key characteristics of P2P push and pull mechanisms to improve the packet delivery ratio and the overall quality of service. Furthermore, we tackle peer heterogeneity using scalable video coding (SVC) that is considered more promising for real-time applications over heterogeneous networks. Our mechanism is evaluated and compared with existing approach. The obtained results show the effectiveness of the proposed overlay organization in term of lowering the packet loss ratio and the delay jitter. This proves the application of our mechanism to live and VoD delivery.

SWOR: An Architecture for P2P Scalable Video Streaming Using Small World Overlay

In this paper we propose SWOR, an architecture to deliver Scalable Video Coding (SVC) contents over P2P network. SWOR architecture is based on twofold mechanisms: (1) organization of peers in Small-World (SW) overlay networks, (2) delivering SVC content using push-pull mechanism. SWOR is evaluated and compared with CoolStreaminglDONet (CS) on QoS metrics using NS-2 simulator. Performance evaluation demonstrates that SWOR outperforms CS and provides a significant improvement in the received video quality in terms of lowering the packet loss and transmission delay.

Differentiated chunk scheduling for P2P Video-on-Demand system

The peer-to-peer (P2P) networks provides a data distribution model that is attractive for Video on Demand (VoD) as it allows to decrease the costs and increase the scalability of video distribution. The two significant challenges in P2P VoD streaming are scalability and video quality. Both require efficient utilization of the resources in P2P network. Inspired by this finding, the paper addresses the problems of chunk scheduling and bandwidth allocation in P2P VoD system to efficiently utilize the upload bandwidth capacity of the peers. We first propose a queue based chunk scheduling mechanism followed by a bandwidth distribution algorithm for urgent downloading and prefetching. Our proposed mechanism allows the maximum utilization of upload bandwidth by distributing the available upload bandwidth among different queues. Experimental results show that differentiated queuing is capable of achieving the optimal streaming rate.

Smooth delivery of layered video stream in P2P networks

Layered streaming in peer-to-peer (P2P) networks has drawn great interests since not only it can accommodate a large number of users but also it handles heterogeneities of peers. However, theres still a lack of comprehensive study on smoothing and layer selection for layered streaming. In this work, we aim to smooth the layered stream by selecting the appropriate layers and reducing the amplitude and frequency of layer changes. We propose three objectives that should be achieved by our proposed mechanism: smoothing, minimizing useless chunk ratio and handling bandwidth fluctuation. The performance evaluation demonstrates that the proposed mechanism provides a significant improvement in the received video quality in terms of lowering the number of layer changes and useless layers chunks.

Network-aware streaming services delivery over ISP-driven P2P networks

The massive exploitation of P2P networks and the deployment of the video streaming services is bringing significant challenges for the service providers and leading to the network efficiency problem to utilize available network resources. In this paper, we propose an ISP-driven P2P framework that enables the better interaction among the ISPs and the P2P application providers. In this framework, the interaction among different entities is facilitated by a topology-aware 2-dimensional overlay network organization driven by the ISPs that is used to organize the participating peers within the network. Furthermore, this ISP-driven overlay organization is used for the streaming service delivery of the Scalable Video Coding (SVC) contents. The proposed framework intends to ensure the improved QoS for the P2P application and enables efficient utilization of the available network resources to benefit the ISPs.

K-overlay: A Kautz Tree Structure for Video on Demand System

In order to improve scalability and reduce maintenance overhead for Peer-to-Peer system, several architecture with constant degree and optimal diameter are proposed. However, the expected topology doesn’t effectively utilize the bandwidth capacity of peers. In this work, we propose K-overlay, an overlay scheme based on unbalanced Kautz graph with logdn diameter and constant in-degree. We define the degree of a digraph as the maximum number of arcs arriving at or leaving from any vertex. The diameter of a graph is the number of arc traversals that is sufficient to reach any vertex from any other vertex. K-overlay structure is based on two-fold mechanism. (1) Organization of peers in concentric circles to maximize the outgoing bandwidth of peers (2) Content delivery through parent as well as neighboring peers. Through formal analysis and comprehensive simulations, we show that our proposed architecture achieves optimal diameter and good connectivity as compared to existing overlay architecture like P2Cast.