Quality Of Multimedia Transmission Research Articles

Evolutionary multiobjective multiple description wavelet based image coding in the presence of mixed noise in images

In this paper, a novel method for generation of multiple description (MD) wavelet based image coding is proposed by using Multi-Objective Evolutionary Algorithms (MOEAs). Complexity of the multimedia transmission problem has been increased for MD coders if an input image is affected by any type of noise. In this case, it is necessary to solve two different problems which are designing the optimal side quantizers and estimating optimal parameters of the denoising filter. Existing MD coding (MDC) generation methods are capable of solving only one problem which is to design side quantizers from the given noise-free image but they can fail reducing any type of noise on the descriptions if they applied to the given noisy image and this will cause bad quality of multimedia transmission in networks. Proposed method is used to overcome these difficulties to provide effective multimedia transmission in lossy networks. To achieve it, Dual Tree-Complex Wavelet Transform (DT-CWT) is first applied to the noisy image to obtain the subbands or set of coefficients which are used as a search space in the optimization problem. After that, two different objective functions are simultaneously employed in the MOEA to find pareto optimal solutions with the minimum costs by evolving the initial individuals through generations. Thus, optimal quantizers are created for MDCs generation and obtained optimum parameters are used in the image filter to remove the mixed Gaussian impulse noise on the descriptions effectively. The results demonstrate that proposed method is robust to the mixed Gaussian impulse noise, and offers a significant improvement of optimal side quantizers for balanced MDCs generation at different bitrates.

Collaborative Multimedia Source-Protocol Coordination: A Cross-Layer QoE Study in Modern Wireless Networks

Multiple image/video source neighbors in modern wireless systems such as device-to-device (D2D) networks can significantly improve multimedia quality of experience (QoE) in content sharing. However, the exploration of multisource diversity in multimedia communications has largely been overlooked in the past. In this paper, we propose a new scheme to improve user equipment's (UE) multimedia QoE by optimizing the source traffic dispatching and resource allocation strategies from multiple UE sources in cross-layer wireless D2D networks while assuring the latency constraint. This approach results in two major contributions. First, the proposed approach optimally controls the source server traffic for each multimedia packet with regard to distortion reduction (e.g., quality contribution) and the channel conditions. Second, optimal packet retry limits are adjusted on each direct D2D communication link to achieve effective but unequal resource allocation. Simulation results show that the cross-layer collaborative source-level traffic control and protocol-level resource optimization strategy improve D2D multimedia transmission quality.

Review of recent standardization activities in speech quality of experience

Speech communication services have been amongst the first telecommunication services to be used by a wide public, and the quality experienced by their users has been an object of concern since then. Methods on how to evaluate quality using test participants or using technical measurements and algorithms have been standardized mostly in Study Group 12 of the International Telecommunication Union (ITU-T SG12) and the Technical Committee Speech and multimedia Transmission Quality (STQ) of the European Telecommunications Standards Institute, ETSI. This paper reviews new and updated ITU-T Recommendations and ETSI documents which have emerged within the last 12 years, and puts them into the general framework of available standards for this type of service. It also discusses current work items of ITU-T SG12 to illustrate directions of thoughts and future Recommendations to be addressed within the next study period.

Apprenticeship Learning Based Spectrum Decision in Multi-Channel Wireless Mesh Networks with Multi-Beam Antennas

We propose a novel spectrum decision scheme (i.e., channel selection and handoff) for wireless mesh networks (WMN) which use multiple channels and nodes equipped with multi-beam directional antennas. Our scheme has the following features: (i) It performs spectrum decision by considering various WMN parameters, including the channel quality, beam orientation, antenna-caused deafness and capture effects, and application priority level. (ii) It uses the reinforcement learning (RL)-based spectrum decision process to achieve the optimal quality of multimedia transmission in the long term. However, a newly-joined WMN node could take a long time to make a correct spectrum decision due to the difficult choice of initial RL parameters. Therefore, our scheme uses the apprenticeship learning in conjunction with the RL model, to speed up the spectrum decision process by choosing a suitable neighboring node (called “expert”) to teach a newly-joined node (called “apprentice”). Our experiments demonstrate that the proposed spectrum decision scheme improves the network performance and multimedia transmission quality.

Qos-Based Optimal Resource Allocation for Multimedia Transmission in Wireless Networks

In this paper, aiming to improve the quality of multimedia transmission while satisfying the quality of service (QoS) requirements, we propose an optimal subcarrier allocation by jointly considering the video coding rate and the available power resource. We jointly analyses the effects on the performance of multimedia transmission from video coding rate at the application layer as well as the power control at the physical layer. This proposed joint power and subcarrier allocation algorithm in MIMO OFDM systems enables us both to overcome the challenge of full CSI (channel state information) with RD (the rate-distortion) to make minimum of the distortion of each users under delay and power constraints. Simulation results show that the proposed optimal subcarrier allocation algorithm improves the multimedia transmission quality considerably through the comparison with the resource allocation algorithms only use a single layer of information.

Merge‐and‐forward: a cooperative multimedia transmissions protocol using RaptorQ codes

Recently, nodes cooperation has emerged as a popular means for improving the quality of multimedia delivery over fifth-generation cellular networks. However, in the conventional relaying scheme such as amplify-and-forward (AaF), there is a higher probability of duplicate packets at the receiver node which affect the decoding probability and consequently deteriorate the quality of multimedia transmission. In this study, the authors propose a cooperative multimedia transmission protocol based on a novel merge-and-forward relaying and the best relay selection (RS) schemes. Their best RS scheme is based on two important parameters: (i) two-hop link distances and (ii) minimum block error rate value. Moreover, to combat the packet loss for enhanced and reliable video delivery, they adopt application layer forward error correction scheme which is based on the most improved and advanced version of fountain codes (i.e. RaptorQ codes). They evaluate the performance of the proposed scheme under different time-sharing scenarios between the direct and best indirect transmission links in terms of decoding failure probability, decoding overhead, peak signal-to-noise ratio, and mean opinion score. Simulation results show that the proposed scheme outperforms the conventional AaF relaying scheme.

Quality-Optimized Joint Source Selection and Power Control for Wireless Multimedia D2D Communication Using Stackelberg Game

In wireless device-to-device (D2D) networks, devices are reluctant to forward packets because of limited energy and possible delays for their own data. The incentive mechanisms that motivate devices to constitute direct communication for wireless multimedia quality optimality in D2D systems have been overlooked in the past. In this paper, we propose a new low-complexity distributed game-theoretic source selection and power control scheme that enhances the multimedia transmission quality with latency constraints. This approach has two major contributions. First, the proposed approach optimally selects the most beneficial source devices by analyzing the interactions between the base station's (BS's) rewarding strategies (denoted by price) and the devices' contributing behaviors (denoted by transmission power) using a Stackelberg game model. Second, optimal transmission power is adjusted for each selected source device in D2D networks by deriving Stackelberg equilibrium, wherein the BS and the device both achieve maximum utility. Computer simulations demonstrate that significant improvement in D2D multimedia transmission quality can be obtained by deploying the proposed scheme.

ACWSN: an adaptive cross layer framework for video transmission over wireless sensor networks

Wireless multimedia sensor networks (WMSNs), have limited resources in terms of computational, memory, bandwidth, and battery capability, which makes transmitting multimedia content over it, is a challenge as multimedia requires QoS guarantee. Recently adopting cross-layer design in WMSNs proved to be a promising approach, which improves quality of service of WSN under various operational conditions. In this work, an adaptive cross layer framework for transmitting multimedia content over WSN (ACWSN) is presented, it is based on an extensive study of Group Of Picture structure effect on quality of multimedia transmission in various wireless channel states that is executed at sink node. It adaptably selects optimum video encoding parameters at application layer according to current wireless channel state which is communicated from physical layer and recommendations communicated from sink node; in addition an AVQ (adaptive video queue) which schedule packets according to its type to drop less important packets in case of network congestion. Simulation results show that ACWSN optimizes video quality in different wireless channel conditions.

Parallelized ACO based Routing for Stagnation Mitigation and Avoidance of Multimedia Traffic Over MANETs

Ant Colony Optimization (ACO) (Deepalakshmi & Radhakrishnan, 2009; Sharma & Kotecha, 2011; Sharma, Karkhanawala, & Kotecha, 2011) is a meta-heuristic, suitable for optimized solutions to routing problem in Mobile Adhoc Networks (MANETs). ACO based algorithms are fully distributed, self-organizing, fault tolerant, and intrinsically adapts to changing traffic patterns. However, if the best path is preferred for routing over longer period of time, the exploratory behaviour of the ants may be affected, thus leading to stagnation of the best paths. The authors have reviewed various techniques used for stagnation control and avoidance (Li, Ma, & Cao, 2005). These include, Pheromone control (Schoonderwoerd, Holland, Bruten, & Rothkrantz, 1996; Wedde & Farooq, 2006; De Rango & Socievole, 2011), Pheromone heuristics control (Sim & Sun, 2003), Privileged pheromone laying (Wedde & Farooq, 2006; Stuzle & Hoos, 2000), Multiple ant colony optimization (De Rango & Socievole, 2011; Sim & Sun, 2003), and Multiple path routing (Upadhyaya & Setiya, 2009b) techniques. They also present a comparative analysis of these schemes with respect to the parameter on which they depend for stagnation avoidance. The paper also focuses on stagnation leading to losses of data, which can lay a drastic effect on the quality of multimedia transmission. The authors propose a scheme to improve the exploratory behaviour of ants, by paralleled release of two streams of forward ants in each iteration, along the path from source to destination. It is mentioned that the technique will improve the quality of multimedia routed through MANETs, due to the multipath based enhancements.

Testbed analysis of video and VoIP transmission performance in IEEE 802.11 b/g/n networks

The aim of the work is to analyze capabilities and limitations of different implementations of IEEE 802.11 technologies (IEEE 802.11 b/g/n), utilized for both video streaming and VoIP calls directed to mobile devices. Our preliminary research showed that results obtained with currently popular simulation tools can be drastically different than these possible in real-world environment, so, in order to correctly evaluate performance of such transfers, a wireless test-bed infrastructure has been created. The results show a strong dependence of the quality of multimedia transmission on the chosen transmission technology and a particular implementation. The overall results demonstrate, that, while multimedia transmission quality in different products is still varied and often requires additional configuration, it is possible to select a WiFi access point model and determine the best system parameters to ensure a good audio/video transfer conditions in terms of acceptable QoP/E (Quality of Perception/Excellence) or MOS (Mean Opinion Score).

Relations between ATM traffic parameters and quality of multimedia transmission - an experimental approach

Relations between ATM traffic parameters and quality of multimedia transmission - an experimental approach