Performance Of Video Streaming Research Articles

QaASs: QoS aware adaptive security scheme for video streaming in MANETs

Real-time video streaming is delay sensitive. It has minimum bandwidth and QoS requirements. Achieving target QoS for video streaming is challenging in a decentralized and self-organized MANET. Cryptography algorithms offer confidentiality of shared data, but they have computation cost. Our work addresses the issue of delay overhead caused by the introduction of cryptography that directly affects video streaming performance. Our proposal is motivated by the possibilities of adaptive security and multimedia service. We make an effort to identify why, when and how to deploy adaptation. We propose QaASs (QoS aware Adaptive Security scheme), an adaptive mechanism that counters the effect of delay overhead by adapting cryptography and multimedia properties, providing QoS while maintaining a required level of security. We evaluate our proposal through implementation and simulation.

Optimizing the Joint Source/Network Coding for Video Streaming over Multi-hop Wireless Networks

Supporting video streaming over multi-hop wireless networks is particularly challenging due to the time-varying and error-prone characteristics of the wireless channel. In this paper, we propose a joint optimization scheme for video streaming over multi-hop wireless networks. Our coding scheme, called Joint Source/Network Coding (JSNC), combines source coding and network coding to maximize the video quality under the limited wireless resources and coding constraints. JSNC segments the streaming data into generations at the source node and exploits the intra-session coding on both the source and the intermediate nodes. The size of the generation and the level of redundancy influence the streaming performance significantly and need to be determined carefully. We formulate the problem as an optimization problem with the objective of minimizing the end-to-end distortion by jointly considering the generation size and the coding redundancy. The simulation results demonstrate that, with the appropriate generation size and coding redundancy, the JSNC scheme can achieve an optimal performance for video streaming over multi-hop wireless networks.

Performance of HTTP video streaming under different network conditions

The Internet video sharing services have been gaining importance and increasing their share in the multimedia market. In order to compete effectively and provide broadcast television with a comparable level of quality, the Internet video should fulfil stringent quality of service (QoS) constraints. However, as the Internet video is based on packet transmission, it is influenced by delays, transmission errors, data losses and bandwidth limitations which can have a devastating influence on the perceived quality of the multimedia content. There are many works which describe the impact of network impairments on the Internet video. Nevertheless, little is known about how network conditions influence the video streamed by the currently popular services such as YouTube, where video is transmitted over reliable TCP/HTTP protocols. Therefore using a network simulator, we conducted an experimental evaluation of the HTTP based video transmission analysing how the network impairments mentioned above influence the streamed video. The experiments were validated against a network emulator supplied with real network traces. As a result of this work, we can state that the buffering strategies implemented by a video player are in many cases able to mitigate unfavourable network conditions what allow to play the streamed video smoothly. The results may serve Internet Service Providers so that they could tune their network characteristics in order to match the demand from HTTP video.

Network Coding-Based Mobile Video Streaming over Unreliable Wireless Links

Today's mobile video streaming performance on wireless networks is choppy due to the unpredictable wireless errors and mobility. In this Letter, we propose a practical online scheduling algorithm for mobile video streaming to multiple users with network coding capabilities. Implementation and analysis results show that our scheme closely approximates the optimal solution both mobile video quality and throughput.

Practical Online Scheduling for Mobile Video Streaming on Smartphones

Mobile video streaming is the killer application for wireless networks. Mobile video traffic accounts for more than 50% of the total traffic on mobile networks and will grow 66-fold over a period of five years. In addition, watching videos over mobile devices such as smartphones and tablets has been attracting interest from users, and demand for mobile video streaming is increasing. However, existing wireless technologies (e.g., WiFi, WiMax, or LTE) cannot support this impending demand. And today’s mobile video streaming performance on wireless networks is choppy due to unpredictable wireless errors and mobility. To support seamless mobile video streaming, several approaches, such as new video codecs, multiple interfaces, metric techniques, novel multiplexing and network coding schemes, were developed. However, these approaches need client modification and did not consider multiple streams sharing the same medium, realistic scenarios and mobility. This paper proposes a practical online scheduling algorithm for mobile video streaming to multiple users with network coding capabilities. Implementation and analysis results show that this scheme closely approximates the optimal solution for both mobile video quality and throughput.

A tool for multimedia quality assessment in NS3: QoE Monitor

Nowadays, with the continuous rise of Internet-based multimedia services, such as video sharing websites, web radios and IP-based telephony, multimedia communications are gaining more and more popularity.From the service provider’s perspective, there is an increasing need in providing high-quality content; at the same time, from the network provider’s view, the requirement is to design networks that can effectively support these services with adequate quality-of-service (QoS). In both cases, engineers and researchers need suitable planning tools exploitable for providing appropriate designs.For all these reasons, we have focused our work on the design and implementation of a novel open-source tool, named QoE Monitor, which consists of a new module for the NS-3 simulator that can be used to perform objective and full-reference quality-of-experience (QoE) assessments in any simulated network. The goal of this tool is to predict the video and/or audio quality perceived by an end user through objective metrics. Moreover, its open-source nature foster its validation and promote knowledge sharing within the research community, while its modularity eases the implementation of additional software components to expand its capabilities (e.g., to account for new codecs and/or new QoE metrics).In this paper, a detailed description of this tool is done and some numerical results about video streaming performance evaluations are presented, which show its effectiveness for the QoE analysis.

Increasing uplink broadband video streaming protocol performance in WiMAX network

WiMAX as a broadband wireless access technology is used increasingly for last mile infrastructures, including video distribution network. Although WiMAX offers high bit-rate wireless connectivity, wireless interference remains an issue. Various transport layer protocols have been proposed to enhance wireless video streaming performance, including re-transmission-based protocol. However, re-transmission yields additional delay, which is not expected in a real-time environment. This paper proposes a cross-layer approach to improve uplink broadband video streaming protocol. The proposed method is aimed at reducing delay caused by the packet loss re-transmission, and to enhance the video quality by implementing the cross-layer bandwidth request. NS-2 simulations demonstrate the significance of the proposed method.

Multisource Video On-Demand Streaming in Wireless Mesh Networks

We study the multisource video on-demand (VoD) application in multichannel multiradio wireless mesh networks. When a user initiates a new video request, the application can stream the video not only from the media servers, but also from the peers that have buffered the video. The multipath multisource video on-demand streaming has been applied in wired networks with great success. However, it remains a challenging task in wireless networks due to wireless interference. In this paper, we first focus on the problem of finding the maximum number of high-quality and independent paths from the user to the servers or peers for each VoD request by considering the effect of wireless interference. We formulate it as a constrained maximum independent paths problem and propose two efficient heuristic path discovery algorithms. Based on the multiple paths discovered, we further propose a joint routing and rate allocation algorithm, which minimizes the network congestion caused by the new VoD session. The algorithm is aware of the optimization for both existing and potential VoD sessions in the wireless mesh network. We evaluate our algorithms with real video traces. Simulation results demonstrate that our algorithm not only improves the average video streaming performance over all the coexisting VoD sessions in the network, but also increases the network's capacity of satisfying more subsequent VoD requests.

A Novel Priority Based Packet Scheduling Scheme for Video Streaming over WiMAX Networks

A priority based packet scheduling scheme for video streaming (rtPS) over WiMAX networks, which corporate with a resource allocation algorithm, has been proposed in this paper. After resource allocation algorithm allocates all the resources available among service flows, packet scheduling algorithm schedules packets in each packet queue according to current byte loss rate of video streaming queue. Priorities of the video packets in the queue and delays of these packets until all the resources for this flow are used up. Simulation results show that the proposed algorithm has better performance for video streaming and can protect the packets which have higher priority from being left, so the video quality has some improvement.

Congestion-aware quality-adaptive streaming of scalable video

Internet video streaming is a hot topic in multimedia systems. A large variety of devices (computers, mobile phones, TVs, etc.) are connected to the Internet via wired or wireless networks and are capable of receiving and decoding HD video content. To enable new services like HD video streaming (e.g., online video rental), the Internet’s infrastructure was enhanced. But the Internet is still a best-effort network, which does not implement quality-of-service or admission control, resulting in time-varying bandwidth and packet delay, packet loss and network congestion. Because video streaming accounts for a considerable amount of the Internet’s traffic, video streaming needs additionally to be congestion-aware, to avoid a congestion collapse of the Internet. The Transmission Control Protocol (TCP) can adapt to changing network conditions and is currently the de facto standard protocol for congestion-aware and reliable data transmission in the Internet. This fact gave TCP-based video streaming a huge momentum. Consequently, this thesis investigates TCP-based adaptive video streaming for the Internet. The main goal is to provide a solution for congestion-aware video streaming, while still being able to achieve a reasonable performance in error-prone networks. To complement existing work on congestion-aware adaptive streaming, this thesis makes six contributions. (1) The baseline performance of TCP-based adaptive streaming is identified by means of an evaluation of different adaptive streaming approaches. The results represent a reference for further investigations. (2) An investigation on the influence of TCP’s behavior in presence of packet loss on the video streaming performance. (3) To overcome the shortcomings of TCP-based video streaming (single TCP connections fail to deliver a good performance in case of packet loss), a new approach to video streaming based on multiple request-response streams was introduced. The novelty of this system is that it is able to make use of multiple HTTP-based request-response streams while still providing TCP-friendliness. (4) A performance model of the HTTP-based request-response streams was developed, to estimate the influence of the system parameters and the network characteristics on the throughput performance. (5) A comprehensive evaluation of the HTTP-based request-response streams under diverse network conditions was conducted, to validate the model’s estimations. Additionally, the TCP-friendliness was evaluated, showing that request-response streaming systems can be configured to achieve TCP-friendliness. (6) A cellular network with high bandwidth fluctuations and RTTs was used to investigate the performance of the request-response streaming system in a mobile video streaming scenario. The results indicate that the streaming system can make good use of the available bandwidth, while the number of quality switches is kept low. While aggregating multiple TCP connections to improve the TCP streaming performance is quite common, usually the improvement comes at the cost of high deployment effort. By placing the streaming logic at the client, request-response streams can avoid this complexity. Additionally, this client-driven approach responds faster to changing network conditions and enables easy recovery from connection stalls or aborts, because the control loop is at the client. To improve the network efficiency and the scalability in terms of number of clients served, HTTP-based request-response streams can utilize HTTP proxies and caches.

Design of Efficient Multicast Protocol for IEEE 802.11n WLANs and Cross-Layer Optimization for Scalable Video Streaming

The legacy multicasting over IEEE 802.11-based WLANs has two well-known problems-poor reliability and low-rate transmission. In the literature, various WLAN multicast protocols have been proposed in order to overcome these problems. Existing multicast protocols, however, are not so efficient when they are used combining with the frame aggregation scheme of IEEE 802.11n. In this paper, we propose a novel MAC-level multicast protocol for IEEE 802.11n, named Reliable and Efficient Multicast Protocol (REMP). To enhance the reliability and efficiency of multicast services in IEEE 802.11n WLANs, REMP enables selective retransmissions for erroneous multicast frames and efficient adjustments of the modulation and coding scheme (MCS). In addition, we propose an extension of REMP, named scalable REMP (S-REMP), for efficient delivery of scalable video over IEEE 802.11n WLANs. In S-REMP, different MCSs are assigned to different layers of scalable video to guarantee the minimal video quality to all users while providing a higher video quality to users exhibiting better channel conditions. Our simulation results show that REMP outperforms existing multicast protocols for normal multicast traffic and S-REMP offers improved performance for scalable video streaming.

Cooperative Error Control Mechanism Combining Cognitive Technology for Video Streaming Over Vehicular Networks

Video streaming over vehicular networks is an attractive feature to many applications, such as emergency video transmission and inter-vehicle video transmission. Vehicles accessing road-side units have a few seconds to download information and experience a high packet loss rate. Hence, this paper proposes Cooperative Error Control (CEC) mechanism combining Cognitive Technology (CT) for video streaming over wireless vehicular networks. CEC mechanism combining CT uses a cooperative error recover scheme to recover lost packets not only from a road-side unit which uses the primary channel but also from the other vehicles using a free channel. Hence, CEC mechanism with CT can enhance error recovery performance and quality of video streaming over vehicular networks. Simulation results show the error recover performance of the CEC mechanism combining CT performs better than the other related mechanisms.

Experimental assessment of the effects of cross-traffic on Wi-Fi video streaming

Wi-Fi networks are the first and sometimes only choice for the video streaming in homes, airports, malls, public areas and museums. However, Wi-Fi networks are vulnerable to interference, noise and have bandwidth limitations. Due to the intrinsic vulnerability of the communication channel, and the large number of variables involved, simulation alone is not enough in the evaluation of the performance of wireless networks. Actually, there is a tendency to give experimental tests a central role in the assessment of Wi-Fi networks performance. The paper presents an experimental analysis of the effects of cross traffic on the performance of video streaming over Wi-Fi, based on cross-layer measurements. Experiments are carried out in a semi-anechoic chamber, to prevent the results from being influenced by external factors. The experimental results permit to analyze the influence of cross traffic characteristics on cross layer measures and objective video quality metrics evaluated through a standardized approach.

무선 멀티 홉 비디오 스트리밍을 위한 모니터링 기반의 네트워크 적응적 FEC 코디네이션

무선멀티홉네트워크(WMNs)는 무선 채널의 페이딩 및 가변적인 대역폭에 의해 패킷 손실 및 전송 지연에 의해 비디오 스트리밍의 성능이 저하된다. 고품질의 비디오 스트리밍의 성능을 보장하기 위해 FEC (Forward Error Correction) 기반의 네트워크 적응적인 비디오 스트리밍 기법이 제안되어 왔다. 종단간 FEC와 홉간의 FEC 기법 등을 사용하는 기존 네트워크 적응 기법들은 제한적인 모니터링 정보에 기반 하므로 스트리밍 경로의 전체적인 상태를 반영하기 힘들다. 본 논문에서는 WMNs 환경에서 모니터링 기반의 네트워크 적응적 FEC 코디네이션을 이용하여 모니터링을 통해 경로 전체의 네트워크 상태를 판별한 후 적응적으로 특정 홉으로부터 종단까지 제어하는 H2E(hop-to-end) FEC 기법을 제안한다. H2E-FEC 기법은 FEC의 시작노드와 중복도(redundancy)를 네트워크 상태에 따라 적절히 결정해야 하며, 이를 위해 중앙집중형 코디네이터를 활용해 획득한 정확한 모니터링 정보를 바탕으로 H2E-FEC를 위한 코디네이션을 적용한다. 제안된 기법은 OMF(Orbit Measurement Framework) 기반의 WMN 테스트베드에서 다수의 실험을 통해 검증하며, 강압적인 네트워크 환경에서 H2E-FEC가 기존의 E2E 및 HbH-FEC 기법에 비해 패킷 복구율 및 전송 지연 시간에 의한 복잡성에서 높은 성능을 나타낸다. 구축된 테스트베드 환경에서 코디네이터를 적용한 후 E2E-FEC 기법에 비해 패킷 복구율이 약 17% 향상됨을 보인다. Video streaming over wireless multi-hop networks(WMNs) contains the following challenges from channel fading and variable bandwidth of wireless channel, and it cause degradation of video streaming performance. To overcome the challenges, currently, WMNs can use Forward Error Correction (FEC) mechanism. In WMNs, traditional FEC schemes, E2E-FEC and HbH-FEC, for video streaming are applied, but it has long transmission delay, high computational complexity and inefficient usage of resource. Also, to distinguish network status in streaming path, it has limitation. In this paper, we propose monitoring-based coordination of network-adaptive hop-to-end(H2E) FEC scheme. To enable proposed scheme, we apply a centralized coordinator. The coordinator has observing overall monitoring information and coordinating H2E-FEC mechanism. Main points of H2E-FEC is distinguishing operation range as well as selecting FEC starting node and redundancy from monitored results in coordination. To verify the proposed scheme, we perform extensive experiment over the OMF(Orbit Measurement Framework) and IEEE 802.1la-based multi-hop WMN testbed, and we carry out performance improvement, 17%, from performance comparison by existing FEC scheme.

Video Streaming Performance Under Well-Known Packet Scheduling Algorithms

Video streaming is becoming increasingly popular among the wireless users. However, supporting video streaming over the wireless networks is not an easy task due to the dynamic radio propagation environment, limited radio resources as well as Quality of Service (QoS) requirements of the video streaming that need to be satisfied at acceptable levels. Most studies proposed to support video streaming are computationally expensive to be used in Orthogonal Frequency Division Multiple Access (OFDMA) based wireless IP networks. This paper evaluates video streaming performance under three well-known algorithms that are more practical to be used in the OFDMA based wireless IP networks due to their reduced complexity. It is demonstrated via computer simulation that Proportional Fair (PF) algorithm outperforms other well-known algorithms by providing video streaming QoS at acceptable levels whilst maximizing cell throughput.

A genetic approach to Markovian characterisation of H.264 scalable video

We propose an algorithm for multivariate Markovian characterisation of H.264/SVC scalable video traces at the sub-GoP (Group of Pictures) level. A genetic algorithm yields Markov models with limited state space that accurately capture temporal and inter-layer correlation. Key to our approach is the covariance-based fitness function. In comparison with the classical Expectation Maximisation algorithm, ours is capable of matching the second order statistics more accurately at the cost of less accuracy in matching the histograms of the trace. Moreover, a simulation study shows that our approach outperforms Expectation Maximisation in predicting performance of video streaming in various networking scenarios.

The impact of interference-aware routing metrics on video streaming in Wireless Mesh Networks

Wireless Mesh Networks form a wireless backbone that provides ubiquitous Internet access and support of multimedia services. In this scenario, traffic crosses multi-hop paths, through mesh routers and gateways, causing high levels of interference. To address this problem, the use of schemes that introduce routing metrics that take into account the characteristics of the interference have been made to improve the application performance. Given the diversity of interference-aware routing metrics for Wireless Mesh Networks, it is necessary to assess the impact of employing these routing metrics on multimedia traffic performance, and in particular, on video streaming. This paper seeks to fill this gap, by using simulation to evaluate the video streaming performance when the most relevant interference-aware routing metrics are used. The degree of video quality can be evaluated from two perspectives, the network viewpoint and the standpoint of the user perception. At the network level, video streaming quality is assessed through IP measures, that is, throughput, delay, jitter and routing overhead. At the user level, ‘Quality of Experience’ metrics are employed to measure the user perception with regard to the video quality. The evaluation of the performance takes account of outdoor and indoor environments. The results of the simulation study have shown that routing metrics based on the information that detects interference using accurate measures achieve a better network and user perception performance. However, depending on the environment (i.e., whether it is indoor or outdoor), all the routing metrics result in a different performance being achieved. Although interference-aware routing metrics affect the performance of both the network and the user levels, there are some cases where they have less impact on the user level, because the user perception parameters are less influenced by the behaviour of the network.

Resource management for video streaming in ad hoc networks

Video streaming over wireless links is a challenging issue due to the stringent Quality-of-Service (QoS) requirements of video traffic, the limited wireless channel bandwidth and the broadcast nature of wireless medium. As contention-based or reservation-based ( i.e., contention-free) medium access control (MAC) protocols in existing wireless link-layer standards cannot efficiently support multimedia applications such as video streaming, a hybrid approach has been proposed, which uses both contention and reservation-based channel access mechanisms to transmit packets for each video source. Using this content-aware resource management approach, each video source reserves well below its peak data rate, and uses contention-based media access to transmit the remainder of the packets. In this paper, we first propose two conflict avoidance strategies and two buffering architectures for video streaming over ad hoc networks. Considering the interactions of reservation and contention, we develop the analytical model for the saturated traffic case and then extend it to derive tight performance bounds for the unsaturated case. Using the MAC protocols specified in the WiMedia ECMA-368 standard as an example, extensive simulations have been conducted to validate the analysis. Real video traces have been used to examine the video streaming performance. The analytical and simulation results demonstrate the effectiveness and efficiency of the hybrid resource management approach, and also reveal the impact of the conflict avoidance strategy and buffering design on the video performance.

Block level buffer management for video streaming services in IPTV environments

With the widespread adoption of broadband Internet services and recent advances in video technologies, Internet Protocol Television (IPTV) is becoming increasingly popular. IPTV provides a variety of interesting services such as VOD (Video on Demand), PVR (Personal Video Recorder), game, shopping as well as live TV broadcast. In order to support various interactive services of IPTV, more elaborate software should be equipped for video streaming services. Specifically, popularity-based interval caching is effective in improving the performance of video streaming services in IPTV environments. This paper shows that block level refinement of existing schemes can further improve the service quality and performance of video streaming in IPTV. Simulations with real world VOD traces show that the proposed scheme improves the cache hit rate and the response time significantly.

On Energy Efficient Encryption for Video Streaming in Wireless Sensor Networks

Selective encryption for video streaming was proposed for efficient multimedia content protection. However, the issues on joint optimization of video quality, content protection, and communication energy efficiency in a wireless sensor network (WSN) have not been fully addressed in the literature. In this paper, we propose a scheme to optimize the energy, distortion, and encryption performance of video streaming in WSNs. The contribution of this work is twofold. First, a channel-aware selective encryption approach is proposed to minimize the extra encryption dependency overhead at the application layer. Second, an unequal error protection (UEP)-based network resource allocation scheme is proposed to improve the communication efficiency at the lower layers. Simulation experiments demonstrate that the proposed joint selective encryption and resource allocation scheme can improve the video transmission quality significantly with guaranteed content protection and energy efficiency.