High-quality Video Streaming Services Research Articles

A multi-layer probing approach for video over 5G in vehicular scenarios

Fifth generation (5G) technologies are becoming a reality throughout the world. In parallel, vehicular networks rise their pace in terms of utilization; moreover, multimedia content transmissions are also getting an always increasing demand by their users. Besides the promised performance of 5G networks, several questions still arise among the community: are these networks capable of delivering high quality video streaming services in moving scenarios? What is the relationship between the network conditions and the video quality of experience?To answer to the previous questions, in this paper we propose a multi-layer probing approach able to assess video transmissions over 5G and 4G, combining data from all layers of a communication model, relating events from its origin layers. The probe's potential is thoroughly evaluated in two distinct video streaming use cases, both targeting a vehicular scenario supported by cellular 4G and 5G networks. Regarding the probe's performance, we show that a multitude of performance and quality indicators, from different stack layers, can be obtained. As for the performance of 4G and 5G networks in video streaming scenarios, the results have shown that the 5G links show a better overall performance in terms of video quality-of-experience, granting lower delays and jitter conditions, thus allowing video delay to be diminished and segment buffering to be better performed in comparison to 4G, while still showing adaptability in lightly traffic-saturated vehicular-to-vehicular scenarios.

Particle Swarm Optimization Video Streaming Service in Vehicular Ad-Hoc Networks

Owing to the increasing capabilities of mobile devices and the development of mobile communication techniques in vehicular ad hoc networks (VANETs), mobile multimedia services have focused on supporting high Quality of Service (QoS) and Quality of Experience (QoE) for the subscribers in video streaming services. In VANETs, high-quality video streaming services aim to provide safety, as well as various infotainment applications to the subscribers. Owing to the dynamic topology and frequent connectivity changes in moving vehicles, video streaming services require elastic and continuous updates of vehicle information to present interactive real-time views of nontrivial scenarios on roads. To achieve high QoS and QoE of video streaming services in VANETs, this paper proposes a novel protocol named PSOstreaming that is based on a particle swarm optimization (PSO) which is one one of the mainstream and nature-inspired algorithms for swarm intelligence (SI). PSOstreaming calculates the PSQ score, which is the scoring method of the node in the topology in terms of the data communication capability measurement to analyze and optimize topology information in real-road circumstances. In addition, PSOstreaming utilizes a 3D vector mobility prediction algorithm for the mobility prediction method for the vehicles to address the characteristics of VANETs. In the topology, PSOstreaming defines Global PSO members and Local PSO members to disseminate video packets for video-streaming services to the service requester by computational equations. Experimental results indicate that PSOstreaming achieves high-quality video streaming services with a flexible response to dynamic topology changes and a high frame delivery ratio in terms of QoS and QoE.

Video Packet Distribution Scheme for Multimedia Streaming Services in VANETs.

By leveraging the development of mobile communication technologies and due to the increased capabilities of mobile devices, mobile multimedia services have gained prominence for supporting high-quality video streaming services. In vehicular ad-hoc networks (VANETs), high-quality video streaming services are focused on providing safety and infotainment applications to vehicles on the roads. Video streaming data require elastic and continuous video packet distributions to vehicles to present interactive real-time views of meaningful scenarios on the road. However, the high mobility of vehicles is one of the fundamental and important challenging issues for video streaming services in VANETs. Nevertheless, previous studies neither dealt with suitable data caching for supporting the mobility of vehicles nor provided appropriate seamless packet forwarding for ensuring the quality of service (QoS) and quality of experience (QoE) of real-time video streaming services. To address this problem, this paper proposes a video packet distribution scheme named Clone, which integrates vehicle-to-vehicle and vehicle-to-infrastructure communications to disseminate video packets for video streaming services in VANETs. First, an indicator called current network quality information (CNQI) is defined to measure the feature of data forwarding of each node to its neighbor nodes in terms of data delivery ratio and delay. Based on the CNQI value of each node and the trajectory of the destination vehicle, access points called clones are selected to cache video data packets from data sources. Subsequently, packet distribution optimization is conducted to determine the number of video packets to cache in each clone. Finally, data delivery synchronization is established to support seamless streaming data delivery from a clone to the destination vehicle. The experimental results show that the proposed scheme achieves high-quality video streaming services in terms of QoS and QoE compared with existing schemes.

Multipath-Based HTTP Adaptive Streaming Scheme for the 5G Network

Fifth-generation (5G) communication has a non-line-of-sight (non-LOS) property, in that it cannot pass through obstacles due to the characteristics of ultra-high frequencies. This can lead to a high packet loss rate, which results in loss-based congestion. As the demand for high-quality video streaming services increases, multipath-based Hypertext Transfer Protocol (HTTP) adaptive streaming has been widely studied. It has the advantage of improving stability using bandwidth aggregation and alternative transmission. The request policies of existing systems degrade bandwidth utilization by the ON-OFF traffic pattern and degrade the quality-of-experience (QoE) due to incorrect bandwidth estimation. In the 5G environment, the above problems are exacerbated by severe network asymmetry, and buffer underflow occurs due to the drastic bandwidth changes in a non-LOS environment. We propose a multipath-based transmission scheme to solve the problem of HTTP adaptive streaming in a 5G environment. The proposed scheme presents a multipath-based collective segment request policy for accurate aggregated bandwidth estimation and bandwidth utilization improvement. The aggregated bandwidth estimation measures both block-based and segment-based bandwidth estimation values to improve network responsiveness and stability. We propose a rate adaptation scheme to improve bandwidth utilization and QoE. We also present a segment scheduler to solve the out-of-order problem in multipath-based transmission, and propose an offloading control scheme based on a partial-segment-based request policy to prevent buffer underflow due to sudden bandwidth reduction in the non-LOS 5G environment. Quantitative results from simulations suggest that our scheme solves the shortcomings of the existing solutions improving both bandwidth utilization and QoE.

Dynamic Block-Based HTTP Adaptive Streaming Scheme in Multiple Wireless Networks

Multipath-based hypertext transfer protocol (HTTP) adaptive streaming (MPHAS) has been studied due to the increasing use of mobile devices equipped with multiple network interfaces and the prevalence of high-quality video streaming services. However, the existing MPHAS schemes undergo a degraded quality of experience (QoE) in multiple wireless networks. The segment request-based MPHAS (SR-MPHAS) encounters frequent quality switching, and the block request-based MPHAS (BR-MPHAS) causes results in playback stalling and inefficient bandwidth utilization, according to slow responsiveness. In this paper, we propose a dynamic block-based MPHAS (DBAS) to improve the QoE by overcoming the limitations of the existing schemes in multiple wireless networks. We propose buffer-based block length adaptation and QoE-based block quality adaptation to reduce the frequency of quality switching and to improve the responsiveness to network changes. Moreover, we propose a partial request-based block scheduler to mitigate segment reordering. The experimental results show that the DBAS improves the QoE by reducing the quality switching frequency and rapidly adapting to abrupt changes in the bandwidth.

Stochastic Analysis of DASH-Based Video Service in High-Speed Railway Networks

The latest increasing popularity of high-speed railways (HSR) has stimulated growing demands for wireless Internet services in HSR networks, especially for video streaming. However, due to the high variability and unpredictability of wireless communications in HSR networks, it is still difficult for the existing solutions to provide high-quality video streaming services to HSR passengers. This paper addresses this crucial problem first by reporting on field experiments performed to investigate the characteristics of HSR networks. Then the paper formulates an intractable optimization problem for dynamic adaptive streaming over HTTP (DASH)-enabling service in HSR networks considering various factors, including packet loss, energy consumption, video service quality, etc. By leveraging Lyapunov optimization approaches, the formulated optimization problem is transformed into a queue stability problem which is of high scalability and generality. Moreover, in order to overcome the intractability of the initial optimization problem, the queue stability problem is further decomposed into three subproblems which can be easily solved individually. Finally, a novel joint stochastic DASH optimization (JSDO) mechanism consisting of three algorithms for the derived subproblems is proposed. Rigorous theoretical analyses and realistic dataset-based simulations demonstrate the effectiveness of the proposed JSDO mechanism.

A No Reference Video Quality Metric Based on Jerkiness Estimation Focusing on Multiple Frame Freezing in Video Streaming

ABSTRACTIn wireless networks, due to limited bandwidth and packet losses, seamless and ubiquitous delivery of high-quality video streaming services is a big challenge for the operators. In order to improve the process of online video quality monitoring, the presence of no reference (NR) objective video quality assessment (VQA) methods is required. In some networks, the video decoder on the reception side adopts a mechanism in which last correctly received frame is frozen and displayed on video display terminal until the next correct frame is received. This phenomenon, employed as an error concealment technique, can cause a perceptual jerkiness on the video display terminal. In this paper, we have proposed an enhanced model of objective VQA based on the estimation of jerkiness. A study of three contemporary NR methods, used for objective VQA and online monitoring of videos, has been included along with subjective VQA tests. The subjective tests were performed for a set of video sequences with specific spatial and temporal information. The proposed NR method is based on our careful observations from the subjective test results and our main focus is to cater the effect of multiple frame freeze impairments in video steaming. Comparison with other NR methods shows that the proposed method performs better, in terms of estimating the impact of multiple frame freezing impairments, and has more affinity with the subjective test results.

Network-Aware Reference Frame Control for Error-Resilient H.264/AVC Video Streaming Service

To provide high-quality video streaming services in a mobile communication network, a large bandwidth and reliable channel conditions are required. However, mobile communication services still encounter limited bandwidth and varying channel conditions. The streaming video system compresses video with motion estimation and compensation using multiple reference frames. The multiple reference frame structure can reduce the compressed bit rate of video; however, it can also cause significant error propagation when the video in the channel is damaged. Even though the streaming video system includes error-resilience tools to mitigate quality degradation, error propagation is inevitable because all errors can not be refreshed under the multiple reference frame structure. In this paper, a new network-aware error-resilient streaming video system is introduced. The proposed system can mitigate error propagation by controlling the number of reference frames based on channel status. The performance enhancement is demonstrated by comparing the proposed method to the conventional streaming system using static number of reference frames.

Quality-Aware Cooperative Proxy Caching for Video Streaming Services

By applying a proxy mechanism widely used in WWW systems to video streaming systems, low-delay and high-quality video distribution can be accomplished without imposing extra load on the system. The video streaming system proposed in this paper consists of a video server and multiple proxy servers. In our mechanism, proxies communicate with each other and retrieve missing video data from an appropriate server by taking into account transfer delay and offerable quality. In addition, the quality of cached video data is adapted appropriately at a proxy to cope with the client-to-client heterogeneity in terms of the available bandwidth, end-system performance, and user preferences on the perceived video quality. Through simulation experiments, it is shown that our proposed mechanism can provide users with low-delay and highquality video streaming services. Furthermore, to verify our mechanism, we implement a real system for MPEG-4 video streaming services and show that our proxy caching system can provide users with a continuous video distribution under dynamically changing network conditions.

A Priority Selected Cache Algorithm for Video Relay in Streaming Applications

With the popularization of Internet, many users can obtain various multimedia services through heterogeneous Internet. Among these services, video streaming application is the most challenging. Because of time constraint and variable bit rate (VBR) property of a video, the problem of streaming high quality video is insufficient external WAN bandwidth. Therefore, it is difficult to expand high quality video streaming services. To solve this problem, we proposed a novel video cache algorithm, called the Optimal Cache (OC) algorithm, for a relay video proxy. By caching portions of a video in a relay video proxy closed to clients, the video playback quality can be guaranteed and the problem of insufficient WAN bandwidth across Internet is eliminated. However, data packets are often lost while streaming video data across Internet, which downgrades video playback quality and even halts the video playback. In this paper, we refine the OC algorithm and propose a novel Priority Selected Cache (PSC) algorithm to select maximum high priority video data for caching in a relay video proxy. The PSC algorithm reduces the decoding errors caused by packet loss, improves error recovery, and provides QoS-guaranteed video playback. On the basis of experiment results with testing several benchmark videos, we show that the PSC algorithm caches at least 15% more high priority video data in a relay video proxy than conventional OC algorithm. Additionally, the PSC algorithm uses minimum storage in a relay video proxy and reduces the maximum bandwidth requirement in the WAN (as does the OC algorithm) subject to QoS-guaranteed video playback

Application-Coexistent Wire-Rate Network Monitor for 10 Gigabit-per-Second Network

To apply network monitoring functions to emerging high-quality video streaming services, we proposed an application-coexistent monitor (APCM). In APCM, a streaming server can works as an active monitor and a passive monitor. In addition, IP packets sent from the server carry monitoring information together with application's data such as video signals. To achieve APCM on a 10-Gbps network, we developed a network interface card for an application-coexistent wire-rate network monitor (AWING NIC). It provides (1) a function to append GPS-based accurate timestamps to every packet that streaming applications send and receive, which can be used for real-time monitoring of delays and inter-packet gap, and (2) functions to capture and generate 10-Gbps wire-rate traffic without depending on packets' size, achieved by our highly-efficient DMA-transfer mechanisms. Such monitoring capability are unprecedented in existing PC-based systems because of the limitation in PC system's architecture. As an evaluation of APCM in an actual network, we conducted an experiment to transmit a 6-Gbps high-quality video stream over an IP network with the system in which we installed the AWING NIC. The results revealed that the video stream became highly bursty by passing through the network, and the observed smallest inter-packet gap corresponds to the value of 10-Gbps wire-rate traffic, which supports the effectiveness of our development.