This paper considers the transmission performance of multimedia streams, especially Scalable Vide... more This paper considers the transmission performance of multimedia streams, especially Scalable Video Coding (SVC), over mobile WiMAX networks. SVC supports temporal, spatial, and quality scalabilities at bit-stream level, which enables the easy adaptation of video by selecting the sub-sets of bit-stream. Thus, SVC streams are more suitable than non-scalable bit-streams in the mobile environment where network conditions are dynamic. In this work, we firstly set up a simulation platform, which integrates NS-2 WiMAX module with EvalSVC evaluation tool set. Then, we design scenarios involving multiple Mobile Stations (MS) and handover to evaluate the performance of video streaming. After intensive simulation tests, we compare the throughput and the packet delay in the different connection scenarios, and count the frame loss of the received video. The simulation results indicate that, in terms of frame loss, the number of MSs is critical to the performance of video transmission. Moreover, handover imposes great influence on video stream transmission.
A Metadata-Based Approach for Multimedia Service Mashup in IMS
Abstract This paper addresses the important issues related to content delivery and service aggr... more Abstract This paper addresses the important issues related to content delivery and service aggregation. We present a metadata-based approach for content and service combined delivery through IP Multimedia Subsystem (IMS). In our approach, the CAM4Home metadata ...
The great success of social technologies such as media sharing, blogs and wikis, is transforming ... more The great success of social technologies such as media sharing, blogs and wikis, is transforming the Internet into a collaborative community. This paper presents our research towards the exploitation of P2P networks, semantic metadata and social tagging for home media sharing, with a vision of P2P-based Collaborative Home Media Community (CHMC). The goal of the proposed CHMC is to enable sharing, searching and tagging of multimedia contents based on semantic metadata within home networks as well as between homes connected by broadband networks. We will firstly present a hierarchical P2P network architecture where the super-peer model is applied. The super peers act as a gateway bridging the inner home network with the external Internet. We further propose the Resource Description Framework (RDF) triple-based metadata indexing, retrieving and tagging algorithms on structured P2P networks. Finally, a prototype is developed for the purposes of system validation and performance evaluation.
Perception-Based Application Layer Multicast Algorithm for Scalable Video Conferencing
In this research work, a new application layer multicast algorithm using distributed service arch... more In this research work, a new application layer multicast algorithm using distributed service architecture and scalable video coding is proposed for scalable video conferencing services. The proposed algorithm considers the limitations of the human perception while participating in a video conference so as to minimize traffic that is not necessary for the communication session. A theoretical analysis was conducted to compare the total waiting time between a centralized and a distributed queues. The result shows that distributed service architecture can, by applying the newly proposed multicast algorithm provide a much smaller delay than the centralized service architecture.
Cost function is an essential part in Application Layer Multicast (ALM) routing algorithms. It is... more Cost function is an essential part in Application Layer Multicast (ALM) routing algorithms. It is from a cost function that we can calculate links' costs and then build the data delivery tree for multicasting. Unfortunately, cost function remains an almost untouched research area in ALM routing. In this research, we propose a new multi-variable cost function considering various end-to-end QoS parameters simultaneously. The mathematical derivation process is also described in details so that one can apply it to obtain other multi-variable cost functions according to their specific requirements. The newly proposed multi-variable cost function can avoid congestion before it happens, preventing the data delivery tree from being frequently or unnecessarily changed while still be adaptable to the dynamic requirements of different applications. With theoretical analysis, we have proved that the new cost function can provide better performance for ALM routing algorithms compared to conventional cost functions.
Scalable Video Coding is the multi-layer extension of Advanced Video Coding with the advantage of... more Scalable Video Coding is the multi-layer extension of Advanced Video Coding with the advantage of providing visual services for customers with heterogeneous network conditions and terminals' capabilities. In this research, advanced features of Scalable Video Coding are investigated and compared with Advanced Video Coding. A new video transmission evaluation platform is proposed to support the latest Network Abstract Layer Units of Scalable Video Coding. A new interface between the scalable video evaluation platform and an overlay simulation platform is developed so that the transmission performance of Scalable Video Coding bit-streams on an overlay network will be evaluated. Both structural similarity index (SSIM) and peak signal-to-noise ratio (PSNR) measurements are applied to evaluate the performance of the video transmission session. New measurement results are also provided so that other SVC-based service designers can select the right video scalability for their service.
Distributed architecture offers many advantages compared to centralized architecture in terms of ... more Distributed architecture offers many advantages compared to centralized architecture in terms of providing multimedia services. However, as a trade-off, distributed architecture requires that peers contribute a portion of their bandwidth and computational capacity to maintain the mutual overlay interconnection. This requirement develops into a serious problem for mobile users and wireless infrastructure, as the radio resource in this network is tremendously expensive, based on 3gpp , and is one of the reasons why distributed architecture has not been widely applied in next-generation (4G) networks. It is also the main reason why multimedia services such as video conference have to rely on a costly centralized architecture built over an expensive media resource function controllers via the Internet protocol (IP) multimedia subsystem (IMS). This research work proposes a new distributed architecture utilizing intelligence and extra capacity, currently available on LTE and WiMAX base stations to reduce the required bit rates that each peer has to provide in order to maintain the overlay network. This reduction saves valuable radio resources and allows a distributed architecture to provide video conferencing services on 4G networks, with all the advantages of a distributed architecture such as flexibility, scalability, smaller delay, and lower cost. In addition, this can be implemented with a minimum modification of the standardized IMS platform and the 4G infrastructure, thereby saving the operators and service providers from excessive investments. A prototype has been built to prove the feasibility of the proposed architecture and evaluate its performances. The results show that our proposed distributed video conferencing service can actually reduce the average bandwidth required for data and signaling messages at wireless mobile terminals while maintaining the main operations of a video conference session.
Scalable Video Coding is the latest extension of the famous Advance Video Coding standard. The ma... more Scalable Video Coding is the latest extension of the famous Advance Video Coding standard. The main advantage of SVC is that it can provide scalability for visual services which are serving customers with heterogeneous network conditions and terminals' capabilities. Nevertheless, the multimedia service research community and industry have not been able to fully utilize the entire potential of this video coding standard extension. One important reason is because of the lack of an evaluation tool-set and platform widely available for usage in the designing, evaluating as well as deploying processes of SVC-based visual services. EvalSVC aims to fill this gap and fosters SVC-based applications and research in multimedia services. It is capable of evaluating the enhanced features (such as spatial, temporal, SNR, and combined scalability) of SVC bit-streams transmitting over real or simulated networks. This tool-set is publicly available.
Application-aware cost function and its performance evaluation over scalable video conferencing services on heterogeneous networks
Video conferencing service requires a multicast tree to distribute its multimedia contents to all... more Video conferencing service requires a multicast tree to distribute its multimedia contents to all participants. Link cost is very important in building such media distribution trees. In this research work, a multi-variable cost function is proposed. This cost function can calculate links' costs based on both network resources and application's requirements. Since participants may join the conference using either a high speed wireless network such as WiMAX or fixed (heterogeneous) networks, we construct a scalable video conferencing service on an overlay network of a simulated Internet topology and a real WiMAX network and apply the newly proposed cost function for building the multimedia distribution tree for the service. Some participants join the conference from the WiMAX network and others from the Internet. An intensive evaluation platform has been built to evaluate the performance of the newly proposed cost function. The collected real measurement data have validated the advanced performance of the new cost function in the rapidly changing heterogeneous network environment.
The Multipoint Control Unit-based centralized architecture and Application Layer Multicast-based ... more The Multipoint Control Unit-based centralized architecture and Application Layer Multicast-based distributed architecture are mainly used for data distribution in video conferencing services. With the contribution of Scalable Video Coding, the latest extension of Advanced Video Coding, video conferencing services are being further researched to support terminals' scalability. The main contribution of this research is to answer a fundamental question before a video conferencing service can actually been designed: which service architecture is more suitable for a SVC-based video conferencing service and in which condition? In order to do that, a framework for evaluating SVC-based video conferencing service has been built; intensive simulation results have been also obtained from simulation scenarios which have been designed from the analysis models of the two scalable video conferencing service architectures. The obtained results show that, with a much higher capacity of the MCU, the MCU-based architecture can only guarantee an almost similar video quality with the ALM-based architecture at a trade-off of at least three times higher end-to-end delay.
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Papers by Tien Anh Le