Video Packets Research Articles

Vbargain: A Market-Driven Quality Oriented Incentive for Mobile Video Offloading

With the increasing popularity of video delivery among mobile users, the problem of explosive traffic growth becomes more and more serious for the mobile wireless networks. To deal with this problem, in this paper we propose to exploit opportunistic transmission and the idea of crowdsourcing to offload mobile video traffic. Based on this idea, a Quality of VIDEO (QoV) oriented pricing incentive scheme, namely Vbargain, is proposed to stimulate mobile users to deliver video data collaboratively. More specifically, in our scheme, the network is regarded as a Virtual Market, and the video packets are treated as commodities, which are dynamically priced according to their expected marginal gains on the quality of reconstructed video; the process of video delivery is regarded as a sequence of packet transactions which are modeled as two-person cooperative games. Driven by the profit-hunting nature of mobile users, the video data is delivered from the source to its destination. In order to gain deep insight into our scheme, we also analyze the overhead and the influence of start-up capital on the performance of video delivered theoretically, and give its lower bound and upper bound. Our simulation results, based on both the synthetic and real-life traces of mobile users, verify the efficiency of our scheme and analysis.

Efficient Mobile Video Streaming via Context-Aware RaptorQ-Based Unequal Error Protection

Mobile video streaming systems typically apply the forward error correction (FEC) at the application layer to cope with packet-level transmission errors, which complements the bit-level correction mechanisms at the physical layer. However, most existing works fail to exploit the block-level dependencies in both intra and interframe coding modes of a single-layer compressed video, and thus are less efficient for the prevailing H.264/AVC and/or H.265/HEVC compatible single-layer video application. To this end, we propose a low-complexity FEC, i.e., context-aware RaptorQ (CA-RQ) with unequal error protection (UEP), to improve the error recovery performance of the single-layer mobile video streaming, through incorporating the block-level dependencies in the compressed video data. We use a packet-level video transmission distortion model that considers the dependencies in both spatial and temporal domains, to quantify the importance of video packets within a group of pictures (GoP). The compressed video packets are categorized and grouped into several classes according to their importance to construct the CA-RQ code with the UEP property. We provide a theoretical analysis on redundancy allocation bounds to demonstrate the superior performance of proposed CA-RQ over the standard RaptorQ code. In the meantime, extensive simulations have shown that our scheme not only offers much better subjective visual quality with less than 50% additional redundant symbols as compared to the Macroblock-Based UEP (MB-UEP) scheme, but also outperforms the MB-UEP and classical equal error protection (EEP)-based schemes, by a 0.45% $\sim$ 5.71% and 0.94% $\sim$ 6.78% margin, respectively, in reconstructed quality evaluated using the structural similarity (SSIM) index, across a reasonable range of redundancy proportions.

Maximizing the quality of service in distributed multimedia streaming in heterogeneous wireless network

In a distributed multimedia streaming, QoS plays an important role while transmitting videos from multiple servers to the client. A good QoS is required to provide videos at high resolution and to achieve better video quality, packet loss and delay have to be reduced. In this paper, combined throughput for multiple flows is proposed to increase the quality of service in distributed multimedia streaming (DMSHN). This scheme is used when the user receives the video packets from multiple servers where each connection forms a different flow. Through this scheme, the location where two or more flows combine is identified and the bandwidth in the channel is divided equally between the different flows, thereby increasing the network performance and dynamically adjusting the transmission rates of all the combined flows.

Optimización del ancho de banda en redes BPL usando las técnicas nucleolus y max-min fairness

Las redes BPL (Broadband Power Line) operan bajo el estándar HomePlug AV (HPAV) el cual utiliza las tecnologías CSMA/CA y TDMA como mecanismo de acceso al medio, donde CSMA/CA está destinado para la transmisión de paquetes de datos y TDMA se utiliza para la transmisión de paquetes de voz y video, con el fin de ofrecer adecuados niveles de QoS. Sin embargo, pese a que el HPAV puede alcanzar altas tasas de transmisión, no cuenta con un adecuado mecanismo de asignación de ancho de banda (AB), lo cual afecta considerablemente el rendimiento de la red a medida que aumenta el número de usuarios debido a que únicamente un nodo puede transmitir a la vez. De acuerdo a lo planteado y, considerando que una red BPL puede ser representada como un juego cooperativo de utilidad transferible (UT), en el presente artículo se propone el uso de dos técnicas para la asignación equitativa de ancho de banda: nucleolus y max-min fairness, las cuales forman parte de la teoría de juegos cooperativos. Al realizar el comparativo de las técnicas nucleolus y max-min fairness como estrategia para la asignación de recursos, se encontró que esta última genera los mejores resultados. Además, se pudo evidenciar que la teoría de juegos puede ser considerada como una novedosa estrategia para la optimización de recursos en una red LAN sobre BPL.

Joint rate adaptation and resource allocation for real-time H.265/HEVC video transmission over uplink OFDMA systems

We consider multiuser video communication over uplink orthogonal frequency-division multiple access (OFDMA) systems. A cross-layer algorithm of joint bit allocation, packet scheduling and wireless resource assignment are proposed to minimize the end-to-end expected video distortion. Video rate adaptation is performed under the wireless resource constraints. The target number of encoding bits for each video packet is obtained to minimize the estimated distortion based on the online content-based rate-distortion function. Due to the inaccuracy of the rate control algorithm in H.265/HEVC encoding, the actual number of bits may differ from the target. Accordingly, the actual encoder distortion may deviate from the estimated distortion. Then, we propose an iterative algorithm to re-assign wireless resources based on the actual number of encoded bits to obtain the final resource allocation policy and packet scheduling decision. Numerical simulation results show that our proposed approach significantly outperforms the baseline algorithms in terms of received video quality.

A novel solution for an efficient tele‐collaborating in surgical medical education: Three‐dimensional tele‐immersion systems

AbstractThree‐dimensional tele‐immersion systems for tele‐collaboration in surgical medical education (SME) have not been implemented due to issues of variable bandwidth availability and delay requirements for high real‐time video quality. The proposed solution in this paper aims to implement a three‐dimensional tele‐immersion system for tele‐collaboration in SME with improved video quality, minimized end‐to‐end delay, and an adaptation ratio, to increase tele‐collaboration experience. The proposed system is based on an algorithm that enhances compression, creates bandwidth adaptivity, and leads to low latency (ECBAaLL), to make efficient use of limited network bandwidth and reduce end‐to‐end delay, by introducing a raptor code and an enhanced algorithm based on segmentation. The results achieved in terms of video quality, end‐to‐end delay, and adaptation ratio of the video streams reflect that the proposed new algorithm improves the quality per stream of the real‐time videos by 8% and reduces the end‐to‐end delay of the video packets by 6%‐7% and that, with the new algorithm, the adaptation ratio of the bandwidth‐adapted videos is increased by 4%‐5%. This work focuses on reducing transmission delays and implementing an improved compression algorithm with reduced end‐to‐end delay and high video adaptation. Hence, the outcome is the quality of video streams for available bandwidth budget with minimal end‐to‐end and processing time delays on a real‐time tele‐collaboration environment in SME.

DASH-QoS: A scalable network layer service differentiation architecture for DASH over SDN

As one of the key technologies residing in the future Internet concepts, Software Defined Networking (SDN) makes it possible to develop application-centric flow routing strategies. Thanks to the benefits offered by the SDN architecture, the performance of multimedia communication applications can be improved by developing application-centric flow routing strategies. Recently, MPEG-DASH standard which allows rate adaptation over HTTP has become popular. In this work, we present an architecture that provides increase in received quality of DASH clients running over an SDN domain. Within this architecture, we propose an optimization model which determines the streaming paths of the video packets of the clients. We also define different types of user classes and provide a guaranteed service and fairness among the users of the same class. Furthermore, we created a heuristic algorithm to facilitate the scalability of the solution. The simulation results show that, by considering the output of the optimization model and dynamically changing the routing paths in an ISP, the video quality offered to the DASH clients is significantly improved and a certain level of service guarantee is provided.

Reconfigurable optical‐radio wireless networks: Meeting the most stringent requirements of future communication systems

AbstractIn this paper, we propose a reconfigurable optical‐radio wireless network characterized by high flexibility and performance. The hybrid network can be dynamically configured, adapting itself to the changing requirements of users or operating environments, dynamics of the transmission medium, and availability of resources. First, the basic concept, system architecture, and key operating modes are introduced. Possible operating scenarios and their relationship to the operating modes are discussed. Then, a practical implementation of the hybrid network is introduced, describing the network components, architecture, modulation scheme, and implementation technologies. Implementation was carried out using mostly off‐the‐shelf components and universal software radio peripheral blocks. Particular attention has been put in implementing a fast handover mechanism between modes, an essential requirement for seamless network reconfiguration. Network performance is evaluated and different switching approaches are compared. The paper demonstrates practically the proposed concept based on dynamic system reconfiguration. For the implementation, a mode switching algorithm was developed making decisions based on the quality of the wireless channels. The system was tested with live video packets transmitted through the network. System performance was assessed through data throughput and packet loss measured for different modulation parameters. The proposed concept, essentially a software‐defined hybrid network, is flexible and makes efficient use of radio resources. Moreover, the network has the potential to achieve high performance. All these characteristics make reconfigurable optical‐radio networks an attractive candidate for fifth generation and beyond.

Modeling of image, video and text fusion quality data packet system for aerospace complex products based on business intelligence

For the construction of image, video and text fusion quality data packet system during the whole life of complex products, a business intelligence-based logic modeling method is proposed in this paper. As the amount of Polymorphic data from multiple distributed sources continues to grow exponentially, automation tools are becoming critical to decision makers. The balanced scorecard method is used as the basis for modeling, and the traditional dimensions are modified slightly to meet the requirements of quality data management in aerospace enterprises. A data warehouse with predefined fact and dimension tables is created, and a technical solution is provided to meet the requirements and scales of enterprises. In terms of model applications, any enterprise quality manager can extract value from data in the quality data package system for improvement. Online analytical processing (OLAP) cubes support major tasks, such as key quality feature source tracing and analysis, quality issue data mining and integrated quality data delivery.

Algorithm for Enhancing the QoS of Video Traffic over Wireless Mesh Networks

One of the major issues in a wireless mesh networks (WMNs) which needs to be solved is the lack of a viable protocol for medium access control (MAC). In fact, the main concern is to expand the application of limited wireless resources while simultaneously retaining the quality of service (QoS) of all types of traffic. In particular, the video service for real-time variable bit rate (rt-VBR). As such, this study attempts to enhance QoS with regard to packet loss, average delay, and throughput by controlling the transmitted video packets. The packet loss and average delay of QoS for video traffic can be controlled. Results of simulation show that Optimum Dynamic Reservation-Time Division Multiplexing Access (ODR-TDMA) has achieved excellent utilization of resource that improvised the QoS meant for video packets. This study has also proven the adequacy of the proposed algorithm to minimize packet delay and packet loss, in addition to enhancing throughput in comparison to those reported in previous studies.

Application of congestion avoidance mechanism in multimedia transmission over mesh networks

The unreliable nature and shared multi-media of multi-hop communications cause the deployment of multi-media applications in wireless mesh network (WMN) a thorny problem. For instance, video is usually compressed into a group of frames before transmission, resulting in unrecoverable destruction during the display process. The importance of different frames' type is quite different. However, they are considered as same in most existing WMNs. In this paper, we propose a novel Congestion Avoidance Mechanism for multimedia transmission over 802.11e mesh networks. In our mechanism, we added priority for video packets. According to the significance of frames, we proposed an adaptive mechanism involves the mapping of H.264 video packets to appropriate access categories in IEEE 802.11e standard. Simulation results show that our mechanism improves quality of service (QoS) of multimedia transmission.

物联网下网络视频丢包率到用户体验质量的数学映射模型

物联网下网络视频丢包率到用户体验质量的数学映射模型

Optimized delay threshold scheduler for multimedia traffic over LTE downlink network

Allocation of radio resources is very critical to Long Term Evolution (LTE) mobile network. Therefore, it is essential to design and implement optimum scheduling schemes to satisfy the required Quality of Service (QoS) that is vital for Real Time (RT) applications. In this paper, a new scheduling strategy for supporting both RT and Non-RT (NRT) applications is presented. The proposed scheduling scheme performs the allocation process of the available radio resources at two levels. At the first level of the scheduler, an optimized delay threshold is proposed to efficiently control Resource Blocks (RBs) allocation for video traffic. At this level, all video packets are investigated, and only users with Head of Line (HoL) packets delay greater than the optimized delay threshold will be considered for the allocation process in the next level. However, at the introduced scheduler’s second level, RBs are assigned to RT packets according to HoL delays, based on an enhanced algorithm that depends on Earliest Due Date (EDD) mechanism. The behaviour of the introduced scheduling strategy is investigated and compared to the behaviour of other schedulers considered in this research. Simulation results demonstrate that the introduced two-level scheduling strategy provides the best level of quality for the supported services, especially for RT applications. It provides the lowest Packet Loss Rate (PLR) and packet delay, while achieving the highest throughput when compared to other schedulers considered in this research. In addition, the proposed two-level scheduler achieves the highest efficiency of the spectral and system capacity.

A packet-reordering covert channel over VoLTE voice and video traffics

Covert timing channels hide covert message in some timing behavior of an entity. The most common entity is the inter-packet delays (IPDs) which are modulated to represent the covert message. However, since the IPDs of voice over LTE (VoLTE) traffic are limited within a small range have obvious regularity, modifications to IPDs during modulation are easily detected. Therefore, in this paper, we propose a method for building a VoLTE covert channel, which is based on interleaving reordering of voice packets and video packets over VoLTE mixed traffics. Since the number of video packets in the voice packet interval is random, the covert message can be modulated into the numbers of video packets. Moreover, this method helps to increase the capacity of the covert channel. The approach employs Gray code to improve robustness against network jitter. To achieve the undetectability of the covert channel, the method adopts modular operation and the block composed of voice packet intervals to reduce the distribution difference between the covert traffic and the overt traffic. To deal with different adversary models, two different schemes are designed including the one based on video frames and another based on video packets. The difference between the two schemes is whether the rearranged video packets belong to the same video frame. The experimental results show that this solution can achieve high capacity while keeping undetectable and robust.

QoE-Driven Joint Optimization of Segment Adaptation and Resource Allocation for DASH Clients Over LTE Networks

In this paper, we focus on a comprehensive dynamic adaptive streaming over HTTP (DASH) framework, which consists of video content analysis at the HTTP adaptive streaming server, joint optimization of segment switch and resource allocation at eNodeB, and playback information extraction at the client, to improve the quality of experience (QoE) of the DASH clients over long-term evolution networks. We explore the unique characteristics of each segment by establishing the size-time and size-distortion models based on the video packet information extracted from the encoder rather than modeling the entire video sequence by a fixed function. Video quality, stability, and playback continuity can be predicted and reflected by these constructed models. Considering the above three factors, we develop an accumulative QoE model by calculating and predicting the QoE factors of each segment. Then, the entire framework is formulated as a mixed-integer non-linear programming mathematical model to maximize the total QoE of the DASH clients, where decisions on resource allocation and video segment switch are jointly optimized in a semi-synchronous centralized mode. Resource allocation consists of resource block assignment and modulation and coding scheme selection rather than only determining the resource utilization percentage. To perform the optimization, we develop a low-complexity heuristic algorithm that decomposes the original problem into multiple subproblems. The simulation results show that our proposed algorithms can efficiently improve the QoE level compared with other existing algorithms.

Max-Min Resource Allocation for Video Transmission in NOMA-Based Cognitive Wireless Networks

Non-orthogonal multiple access (NOMA)-based cognitive wireless networks can improve the spectral efficiency to utilize the vacant spectrum resource and exploit the power domain diversity. In this paper, we formulate a max-min resource allocation problem for video traffic in NOMA-based cognitive wireless networks as a mixed integer non-linear programming (MINLP) problem. The max-min video transmission problem is subject to the constraints of maximum accessed user number at each subchannel, total available energy of each secondary user, video encoding characteristics, and interference power threshold. To solve the formulated MINLP problem, we divide it into two subproblems, i.e., a power allocation and secondary user scheduling subproblem, and a video packet scheduling subproblem. First, we apply a successive convex approximation to transform the joint power allocation and secondary user scheduling subproblem into a bi-convex programming problem. Second, the binary search and dual decomposition methods are combined to obtain the approximated optimal power allocation and secondary user scheduling solutions. Finally, we propose a heuristic packet scheduling algorithm. Simulation numerical results show that the proposed algorithm improves the video quality and guarantees the fairness among different secondary users.

Performance Evaluation of Distributed Multi Media Wireless Sensor Network

The demand for multimedia services i.e. audio, video and data with improve QoS and optimum utilization of resources in WSN’s has posed new challenges. As the intensity of traffic increases; it demands for higher bandwidth and dedicated resources to reduce packet loss and delay. There have been analytical models proposed where priorities were assigned to video and voice packets to reduce packet loss and optimize resource utilization. In this paper distributed scheme is proposed to handle video, voice and data packets by having multiple sink nodes. There are shared sink nodes where video, voice and data packets are serviced and dedicated sink nodes only for video and voice packets. The proposed scheme has shown that the packet loss for data packets is higher than voice and video packets. The simulation results show that the performance of the network is improved when priorities are assigned to video and voice packets by giving dedicated resources.

Delay-based cross-layer QoS scheme for video streaming in wireless ad hoc networks

With correlating with human perception, quality of experience (QoE) is also an important measurement in evaluation of video quality in addition to quality of service (QoS). A cross-layer scheme based on Lyapunov optimization framework for H.264/AVC video streaming over wireless Ad hoc networks is proposed, with increasing both QoE and QoS performances. Different from existing works, this scheme routes and schedules video packets according to the statuses of the frame buffers at the destination nodes to reduce buffer underflows and to increase video play-out continuity. The waiting time of head-of-line packets of data queues are considered in routing and scheduling to reduce the average end-to-end delay of video sessions. Different types of packets are allocated with different priorities according to their generated rates under H.264/AVC. To reduce the computational complexity, a distributed media access control policy and a power control algorithm cooperating with the media access policy are proposed. Simulation results show that, compared with existing schemes, this scheme can improve both the QoS and QoE performances. The average peak signal-to-noise ratio (PSNR) of the received video streams is also increased.

Content-aware packet scheduling strategy for medical ultrasound videos over LTE wireless networks

In parallel to the advancements in communication technologies, telemedicine research has continually adapted to develop various healthcare applications. The latest wireless technology Long-Term Evolution(LTE) is being increasingly deployed across developed countries and rapidly adopted by developing countries. In this paper, a content-aware packet scheduling approach for medical ultrasound videos is proposed. The contribution of this work is introducing a utility function based on the temporal complexity of the video frames. The utility function is used with four schedulers to prioritise the video packets based on their temporal complexity and type of frame (e.g. I frame). The results show that the utility function improves the packet delay performance obtained in our simulation when compared with content-unaware approach. Further, gain in average PSNR and SSIM are also observed in the received video quality. Research on content-aware packet scheduling for telemedicine applications over advanced wireless networks is limited and our work contributes towards addressing this research gap.

An end-to-end covert channel via packet dropout for mobile networks

Voice over Long-Term Evolution enables reliable transmission among enormous Internet of Things devices, by providing end-to-end quality of service for Internet protocol–based services such as audio, video, and multimedia messaging. The research of covert timing channels aims at transmitting covert message stealthily to the receiver using variations of timing behavior. Existing approaches mainly modulate the covert message into inter-packet delays of overt traffic, which are not suitable for Voice over Long-Term Evolution, since most of the inter-packet delays of Voice over Long-Term Evolution traffic are of regular distribution, and any modification on inter-packet delays is easy to be detected. To address the issue, in this work, we propose a novel covert timing channel for the video stream in Voice over Long-Term Evolution, which modulates the covert message by deliberately dropping out video packets. Based on the two-dimensional mapping matrix, the blocks of covert message are mapped into dropout-packet sequence numbers. To recover the covert message, the receiver retrieves the sequence numbers of lost packets and identifies them to be translated into blocks of the covert message. To evaluate our scheme, the simulations with different packet loss rates are conducted to validate the undetectability, throughput, and robustness, finally, the results show that this scheme is effective and reliable.