Lujie Zhong

Performance Evaluation of Multimedia Content Distribution Over Multi-Homed Wireless Networks

The growing availability of IP based heterogeneous wireless access technologies coupled with the increasing capabilities of mobile devices is creating opportunities for multimedia distribution. Through its multi-homing feature, the ability to support multiple network connections in a single end to end association, the transport layer Stream Control Transmission Protocol (SCTP) can enable seamless and transparent communication sessions over multiple heterogeneous networks. This paper analyzes the performance of multimedia distribution when making use of two multi-homing SCTP-based approaches: Single Path Transfer and Concurrent Multi-path Transfer, in which a single or all paths within an association are used simultaneously for data transmission. In this investigation various retransmission policies and different parameter sets are used in turn and recommendations are made for achieving best results during video delivery. In order to perform this study a novel realistic evaluation tool-set was proposed and is described, which can simulate video delivery over SCTP. Our simulation results and analysis show how to optimize the transmission of multimedia content over SCTP associations in both single and multipath scenarios.

Performance-Aware Mobile Community-Based VoD Streaming Over Vehicular Ad Hoc Networks

Leveraging the development of mobile communication technologies and increased capabilities of mobile devices, mobile multimedia services have set new trends. To support high-quality Video-on-Demand (VoD) in mobile wireless networks, using virtual community-based approaches to balance the efficiency of content sharing and maintenance cost of performance-aware solutions has attracted increasing research interest. In this paper, we propose a novel Performance-aware Mobile Community-based VoD streaming solution over vehicular ad hoc networks (PMCV). PMCV relies on a newly designed mobile community detection scheme and an innovative community member management mechanism. The former employs a novel fuzzy ant-inspired clustering algorithm and an innovative mobility similarity estimation model to group together the mobile users with similar behavior in terms of playback and movement into mobile communities. The latter introduces the role and task of members, member join and leave, collaborative store and search for resources, and replacement of a broker member. Simulation-based testing shows how PMCV outperforms another state-of-the-art solution in terms of performance.

Socially aware mobile peer-to-peer communications for community multimedia streaming services

Mobile multimedia streaming services have become the main reason behind the latest increase in mobile data traffic worldwide. The enormous user base, frequency of data exchange, and demand for high-quality multimedia content open up new challenges to offer good QoS levels in mobile multimedia streaming systems. This article presents an innovative SMMC that integrates performance factors with aspects such as demand, socialization, mobility, and delivery. Simulation results demonstrate that SMMC achieves high content sharing efficiency and increased QoS levels.

CMT-NC: Improving the Concurrent Multipath Transfer Performance Using Network Coding in Wireless Networks

The growing popularity of multihoming mobile terminals has encouraged the use of concurrent multipath transfer (CMT) to provide network diversity and accelerated content distribution in ubiquitous and heterogeneous wireless network environments. However, CMT severely degrades its performance, which is mostly due to both data reordering required as a result of great path dissimilarity and frequent packet loss due to wireless channel unreliability. Most delivery approaches follow the packet sequence numbers and thereby result in strict in-order and packet-specific reception. Passively adapting to the network variations, those approaches are not general enough to address CMT problems. This paper proposes to apply network coding (NC) principles to CMT, to break the strong binding between data packets and their sequence numbers, and then improve its performance. The proposed CMT-NC solution avoids data reordering to mitigate buffer blocking and compensates for the lost packets to reduce the number of retransmissions. Its specific encoding approach reduces the encoding complexity and fully ensures decoding feasibility. Furthermore, the group-based transmission management enhances the robustness and reliability of the data transfer. Simulation results show how CMT-NC is a highly efficient data transport solution outperforming existing state-of-the-art solutions.

Modeling and optimization of bandwidth supply performance for cloud-assisted video systems under flash crowd

The large-scale and sudden video content access such as flash crowds results in huge bandwidth demand, which severely influence user quality of experience and quality of service of video systems. In this paper, we firstly discuss the main reason of generation of flash crowds for video streaming services and analyze key factor for balance recovery between supply and demand of upload bandwidth. We construct two models: bandwidth supply capacity model of video systems and bandwidth demand model of users, which measures usage amount of bandwidth of the cloud. Based on the built models, we further employ a community-based cooperative caching strategy of video resources to promote supply capacity of upload bandwidth of video systems. Extensive tests show how the proposed cooperative caching strategy achieves much better performance results in comparison with original solution.

A novel energy-efficiency social-inspired video sharing solution in wireless networks

Mobile multimedia streaming services provide rich-content visual resources for the mobile users via ubiquitous access to Internet. The video resource sharing focuses on the matching of appropriate resource supplier for the resource requesters and is a key issue for P2P-based video system scalability and user quality of experience. In this context, leveraging social-driven interaction between mobile users enables the discovery of common interests to improve video content sharing efficiency. In this paper, we propose a novel energy-efficiency social-inspired video sharing solution in wireless networks (ESVS). By the analysis of historical request behaviors of users, ESVS designs an estimation method of relationship between videos and groups the videos into a chain-based tree structure. Based on the constructed video tree, ESVS designs a hybrid resource lookup algorithm including push and pull and a communication quality-aware selection strategy of video suppliers, which improves the communication capacities between requesters and suppliers and reduces the network bandwidth consumption. Simulation results also show how ESVS achieves higher resource lookup success rate, lower startup delay, less packet loss rate, and lower maintenance cost than another state-of-the-art solution.

Interaction-Aware Video Community-Based Content Delivery in Wireless Mobile Networks

The increase in the demand of content quality and the number of mobile users brings new challenges for the multimedia streaming services in wireless mobile networks. The virtual community technologies are promising by grouping the users with common characteristics to get the gains in the performance of resource lookup and system scalability. In this paper, we propose a novel interaction-aware video community-based content delivery (IVCCD) in wireless mobile networks. IVCCD collects and analyzes the interaction information between users to construct user interaction model and further capture the common characteristics in the request and delivery of video content. IVCCD employs a partition-based community discovery scheme to group the mobile users in terms of the common characteristics and uses a community member management mechanism and a resource sharing scheme to achieve low-cost community maintenance and high searching performance. Extensive tests show how IVCCD achieves much better performance results in comparison with other state-of-the-art solutions.

A Novel Contribution-Aware Neighbor-Assist Video Delivery Solution over Mobile Content-Centric Networks

In this paper, we propose a novel contribution-aware neighbor-assist video delivery solution over mobile content-centric network (CNVD). CNVD allows the nodes to build and maintain neighbor relationship with other nodes to share cached video resources and achieve unicast-based video lookup. CNVD constructs an estimation model of contribution of neighbor nodes by investigation of lookup delay, number of cached videos, lookup success rate, and geographical distance. CNVD designs the estimation methods of interest level and lookup capacity of nodes for video content, which enables the nodes to decide whether to build neighbor relationship with other nodes. A maintenance method of neighbor relationship between nodes is proposed, which enables the nodes to update valid time of neighbor relationship in terms of contribution of neighbor nodes and decide whether to remove neighbor relationship in terms of the current valid time of neighbor relationship. Further, CNVD designs a contribution-based video lookup algorithm, which reduces lookup delay and improves lookup success rate. Extensive tests show how CNVD achieves much better performance results in comparison with other state-of-the-art solutions.