MPEG-4 video streaming quality evaluation in IEEE 802.11e WLANs (original) (raw)
Related papers
Experimental Comparison of Wired Versus Wireless Video Streaming over IEEE 802.11b WLANs
2006
In this paper the performance of streaming MPEG-4 video with a video server located on the wired network streaming to wireless clients is compared with the performance of a video server located in the wireless network streaming to wireless video clients. We experimentally investigate the performance for a number of concurrent video streams with varying video frame sizes, frame rates and packetisation schemes. The performance is measured in terms of the key parameters of bit rate, loss rate and mean delay. We show how that there is a trade-off for these parameters for a wired and wireless located server. We show that a wired located server is susceptible to high loss rates when there are a number of concurrent video streams whilst the wireless located server has greater reliability in terms of loss rate but incurs greater delays due to having to compete to access to the medium.
A novel mapping mechanism for MPEG-4 video delivery over IEEE 802.11e networks
Multimedia Tools and Applications, 2015
IEEE 802.11e has been introduced to support quality of service (QoS) in WLANs by allocating different traffics to four access categories. Cross-layer design is a method to improve the transmission quality of multimedia over wireless networks. However, when the fragmented packets of a single frame are allocated to different AC queues, out-of-order delivery may occur. Then the receiving node requires more buffer space to absorb the outof-order packets. Therefore, even with a significance classification mechanism, the quality of the video transmission may still be limited due to the occurrence of out-of-order delivery and the transmission of information that becomes useless to the receiver. Therefore, this work developed a novel mapping mechanism (NMM) to improving the quality of MPEG-4 video delivery over IEEE 802.11e networks. The NMM considers the action that was taken on packet of the video frame that had been previously transmitted to resolve the out-of-order delivery by allocating them to the same AC queue as the previously process if possible. Furthermore, the proposed mechanism NMM takes more aggressive scheme to protect more important frame packets from being dropped. In order to evaluate the quality of MPEG-4 video delivery over IEEE 802.11e networks by the proposed mechanism, this work adopted two evaluation metrics, which is called Peak to Signal Noise Ratio (PSNR) and the ratio of frames loss. The simulation results demonstrate that, in terms of both PSNR and the ratio of frames loss, the proposed scheme outperforms exiting schemes such as EDCA (Enhanced Distributed Channel Access) and adaptive mapping.
Implementation Issues for a Video Streaming Server in Ieee 802.11 e Wlans
Recent years have seen a proliferation of real-time multimedia traffic over a more and more heterogeneous Internet. Video streaming at high, consistent quality over wireless links proves to be a difficult task. Several optimization techniques have been proposed and studied, mostly through theoretical analysis and simulation. This article describes the implementation of a cross-layer H.264 video streaming server and the evaluation of its performance in IEEE 802.11e WLANs. Measurements present the benefits of employing several key cross-layer mechanisms which aim to improve the video transmission quality over wireless links. A cross-layer signaling solution is implemented, which addresses important QoS issues between user-space and the kernel traffic control and device driver components. Network support for efficient multiqueue transmission is enabled in the Linux network driver. In addition, the paper discusses the implementation of an enhanced scheduling scheme for the receive-side, in order to provide prioritization of video streams over elastic traffic, and also for better control of latency and improved throughput for multimedia flows.
Study of the Behaviour of Video Streaming over IEEE 802.11b WLAN Networks
IEEE International Conference on Wireless and Mobile Computing, Networking and Communications, 2006. (WiMob'2006), 2006
The performance of video streaming over WLAN networks is not only influenced by the state of the network but also by the encoding configuration parameters of the video stream, such as the video content being streamed, how the video is encoded and how it is transmitted. In this paper, we analyse the unique delay characteristic of video streaming applications in a WLAN environment. We show that the "burstiness" of video is due to the frame-based nature of encoded video. We show how each video frame is transmitted as a burst of packets that is queued at the Access Point causing the delay to exhibit a sawtooth-like characteristic over time that is related to the frame rate and frame structure of the encoded video. To our knowledge, this sawtooth-like characteristic of video streaming over WLAN has not been previously reported on. In this paper, not only do we consider the end-to-end delay, but more importantly we consider the total delay required to transmit the entire video frame. We present experimental results for VBR and CBR video streams and calculate the upper bounds on video encoding parameters for streaming realtime interactive video over a WLAN.
Journal of Computer-Mediated Communication
The IEEE 802.11 technology has been receiving much interest due to its promising enhancements, which offer to wireless local area networks. Recent research has focused on single hop, access point based environments, and network related key performance indicator (KPI) for performance analysis of ad-hoc networks. But it isn't enough to understand the real time video quality with these KPI to meet the stringent QoS (Quality of Service) requirement for video streaming. Therefore, the authors have extended the analysis to a further level based on real time actual frames of video transmission with subjective and objective video quality testing metrics. In this paper, the authors analyzed the real time video streaming quality for QoS with 802.11e EDCA (Enhanced Distributed Channel Access) specification over 802.11 DCF for MPEG-4 (ffmpeg) in MANET / VANET environment with random mobility and multi-hop scenario. The results show that 802.11e EDCA is better performing for frame delay, frame delivery, frame jitter, PSNR and MOS over 802.11 DCF with very low and medium mobility.
The IEEE 802.11e standard is a complement to the IEEE 802.11 family that provides Quality of Service (QOS) in wireless networks at MAC layer level. For the multimedia applications such as video MPEG4, IEEE 802.11e provides a contention based MAC function EDCF (Enhanced Distributed Coordination Function). EDCF offers differentiated services for different type of traffic flows. In this paper the IEEE 802.11e has been evaluated by using different transport layer protocols; TCP, UDP and RTP for the transmission of MPEG4 traffic on wireless medium using IEEE 802.11e MAC layer protocol in ad-hoc mode. In this work a comparative performance analysis of these transport layer protocols with IEEE 802.11e standard, has been performed using NS2 simulator. The performance parameters measured are throughput, end to end delay and packet drop. The simulation results showed that for MAC layer IEEE 802.11e standard, RTP is the most suitable protocol for the transmission of MPEG4 type video traffic on wireless medium in ad-hoc mode.
The bursty nature of video streaming applications is due to the frame-based structure of video and this has an important impact on the resource requirements of the WLAN, affecting its ability to provide Quality of Service (QoS) particularly under heavily loaded conditions. For video streaming applications, packet loss and packets dropped due to excessive delay are the primary factors that affect the received video quality. In this paper, we analyse the effects of contention on the performance and behaviour of video streaming applications over IEEE 802.11b WLANs. We show that as contention levels increase, the packet delay increases significantly, despite the total offered load in the network remaining the same. The increased delay is shown to be related to the MAC mechanism used in the IEEE 802.11 standard. We also show that the characteristics of the video content significantly affect the degree to which the stream is affected by contention.
Performance Analysis of Video Transmission Over IEEE 802.11a/e WLANs
IEEE Transactions on Vehicular Technology, 2007
This paper presents efficient mechanisms for delaysensitive transmission of video over IEEE 802.11a/e Wireless Local Area Networks (WLANs). Transmitting video over WLANs in real time is very challenging due to the time-varying wireless channel and video content characteristics. This paper provides a comprehensive view of how to adapt the quality of service signaling, IEEE 802.11e parameters and cross-layer design to optimize the video quality at the receiver. We propose an integrated system view of admission control and scheduling for both contention and poll-based access of IEEE 802.11e Medium Access Control (MAC) protocol and outline the merits of each approach for video transmission. We also show the benefits of using a cross-layer optimization by sharing the Application, MAC, and Physical layer parameters of the Open Systems Interconnection stack to enhance the video quality. We will show through analysis and simulation that controlling the contention-based access in IEEE 802.11e is simple to realize in real products and how different cross-layer strategies used in poll-based access lead to a larger number of stations being simultaneously admitted and/or a higher video quality for the admitted stations. Finally, we introduce a new concept called time fairness, which is critical in enhancing the video performance when different transmitter-receiver pairs deploy different cross-layer strategies.